What are the principles of train, bullet train, high-speed rail and magnetic levitation? What is the difference?

In recent years, China has made great efforts to build public transportation, and various modes of transportation, including trains and high-speed rail, have made great progress. At present, there are four main rail transit vehicles in China, namely trains, bullet trains, high-speed trains and maglev trains. So what's the difference between these four modes of transportation? Mainly reflected in their working principle.

1. The train is the oldest of the four, and the earliest train was born in Britain in 18 14. At first, the steam engine was used as power, but due to the pollution of the steam engine, the electric locomotive was formed in the later stage. Modern trains use electric energy, which drives the motor to rotate, thus driving the train wheelset to rotate. In the process of wheelset rotation, friction in the opposite direction is generated between wheelset and rail, which drives the train forward.

Second, bullet trains are similar to high-speed trains and high-speed trains, but there are also differences. Bullet trains often belong to trains, that is, they are improved on the basis of ordinary trains and are only called bullet trains in China. In China, the speed of bullet train is more than 200 km/h, and it is only pulled by the front of the train. High-speed rail belongs to the railway type, and the speed can reach about 300 km/h. The difference between them lies in the different tracks used, one is ballasted track and the other is ballastless track. The dynamic principles of the two are similar, but the requirements for other places, such as tracks and materials used, are different.

Third, the maglev train is special. The maglev train mainly realizes the non-contact suspension and guidance between the train and the track by electromagnetic force. Generally speaking, it is the principle that magnets repel each other. The driving principle is also different from other tools, mainly using the electromagnetic force generated by DC motor to pull the train forward. Because the maglev train is not in direct contact with the track, the friction of the maglev train is very small. The speed is also very high. Normally oriented maglev train can reach 400 km/h, and the speed of superconducting maglev train can even reach 600 km/h, so maglev train will be a new research direction in the future.

The above is an introduction to the principles of these four modes of transportation, and you are welcome to add them.