The archaeological excavation of the Hanwen Emperor's Tomb is a grand event in China's archaeological history, from the data released by the Shaanxi Provincial Archaeological Research Institute, the number of cultural relics excavated from the Hanwen Emperor's Tomb has reached thousands, of which there are more than 1,000 naked clay figurines. In addition to the naked clay figurines with bare and broken arms, there is a delicately polished Han Dynasty bronze gear that is particularly eye-catching, this bronze gear is like a coming through time and space, and the use of this bronze gear is still a mystery so far.
Han Dynasty bronze gears
This Western Han bronze gear excavated from the tomb of Emperor Wen of han is extremely exquisite, and although it has been eroded by more than 2,000 years, it is still smooth as new after being cleaned. It is not the rough appearance of the Han Dynasty bronzes that people have seen before, but the surface is smooth and the teeth are sharp, as if it is a thing that travels through time and space, and is lost there by a modern person.
The exterior of this bronze gear is a circular frame structure with 36 teeth evenly arranged on the circular frame; inside the frame is a cross-shaped bracket with a circular hole in the center of the bracket.
The bronze gear is not very large, and from the released video, the outer diameter of the bronze gear is equivalent to the length of an adult's middle finger. Although experts did not announce the specific size of the gear, it seems from the video that the diameter of the gear does not exceed 10 centimeters.
The bronze gears of the Western Han Dynasty are exquisitely made, and the gaps between the wheel teeth are uniform and compact, indicating that the technology of smelting and casting gears in the Western Han Dynasty has been quite mature.
The invention of the gear
It is impossible to verify which inventor invented the gear, but one thing is recognized, that is, the person who invented the gear is a genius.
Gear is a mechanical element that transmits power through continuous bite, a single gear can not complete the power transmission effect, only two or more gears will form the effect of transmitting power.
In the first century AD, the Roman architect Bidobis made a watermill mill driven by gears, which is the earliest documented application of gear devices.
In fact, china's ancients have invented gears four or five thousand years ago, and there are 29 teeth on the gears excavated at the site of Xiangfen Tao Temple in Shanxi. Around the first century AD, China has also had a record of the application of gears, the Eastern Han Dynasty Zhang Heng (78-139 AD) designed the "water transport hunxiang" is a water as the power, through the transmission of the gear to make the hun elephant rotate around the central axis at a uniform speed. The device rotates once a day to record the time.
By the end of the 19th century, with the advent of machine tools, gear making became more and more simple, and the application of gears began to spread.
Bronze gears unearthed from the Tomb of Emperor Wen of Han advanced the application of gears by at least 300 years from the first century AD. At the press conference, experts did not announce the use of the western Han bronze gear, indicating that the real use of this gear is still debatable.
Not the drive device on the bronze carriage of the Qin and Han dynasties
Will the bronze gears of the Western Han Dynasty be the carriage and horse parts of the Qin and Han Dynasties?
People who have been to the Qinling Museum should have an impression of the Qin Dynasty bronze carriage inside, right? Qinling copper car immediately did have many advanced technology, but the carriage was just a bicycle pulled by horse skin, and the Qinling copper car did not immediately use gears as mechanical transmission devices, so there was no such style of carriage and horse parts on the carriage of the Qin and Han Dynasties.
In addition, the bronze gear excavated from the tomb of Emperor Wen of Han is only 10 centimeters in size, and such a small gear obviously cannot meet the transmission energy needs of the carriage, so the western Han bronze gear can be excluded as the speculation of the driving device on the carriage.
Will it be an accessory on the "Keiri Drum Car"?
There is a record of the drum cart in the Book of Jin: "The drum cart in the book, the frame is four." The shape is like Sinan. Among them, there are wooden people who hold a hammer to the drum, and a hammer for a mile. ”
From this description, it can be seen that the drum car is installed on the frame of the car, and the puppet will strike the drum once for each mile of travel, and record the mileage of the carriage with the number of drums, which is equivalent to the odometer on modern cars.
The Drum Truck is a metering device that records the number of rotations of wheels by reducing gears. Its principle is to install a vertical shaft on the wheel, and the gears on the vertical shaft mesh with the gears in the puppets above the carriage. Due to the different sizes of the gears on the carriage, the number of teeth on the gears is also different, so the number of turns turned is also different. When the vertical shaft rotates, the large and small gears mesh and rotate, and the gears are passed down one by one to form a deceleration system. When the car is walking exactly one mile, the middle flat wheel is just turning in a circle, and the short nails on it will pluck the puppet's drum stick, and it will hit the drum and record the mileage by the number of drum sounds.
Could the bronze gears unearthed in the tomb of Emperor Wen of Han be the deceleration gears on the drum cart? This conclusion has yet to be studied and explored by scientists and archaeologists.
The significance of the bronze gears of the Western Han Dynasty
The discovery of bronze gears in the Western Han Dynasty proves that China has mastered the manufacture and use of gears in the Western Han Dynasty, although it is not clear the real use of this gear, but this exquisite bronze gear shows us the true level of handicraft industry and smelting industry in the Western Han Dynasty, providing an important physical basis for experts to study the development of science and technology at that time.
It is believed that with the continuous advancement of the archaeological work of the Han Wen Emperor's Tomb, more cultural relics will be unearthed one after another, and the real use of this bronze gear will definitely be cracked by experts.