The escalator's core components are two chains that rotate around two pairs of gears. At the top of the escalator, there is an electric motor driving the gear to turn the chain. A typical escalator uses a 100 horsepower engine to turn gears. Engines and chain systems are installed in trusses, which refer to metal structures extending between two floors.

      Unlike a conveyor belt moving a plane, the chain moves a set of steps. The most interesting thing about escalators is how they move. When the chain moves, the steps keep level. At the top and bottom of escalator, steps are folded together to form a platform. This makes the escalator up and down easier.

      Each step on the escalator has two sets of wheels, which move along two separate orbits. The upper device (the wheel near the top of the step) is connected with the rotating chain and is pulled by the driving gear located at the top of the escalator. The wheels of other groups only slide along the track, following the first group of wheels.

     The two tracks are separated from each other so that each step can be kept horizontal. At the top and bottom of the escalator, the track is horizontally positioned to flatten the steps. A series of grooves are arranged inside each step to connect the front and back steps in the course of flattening.

     Besides rotating the main chain ring, the motor in the escalator can move the handrail. The handrail is just a rubber conveyor belt that revolves around a series of wheels. The conveyor belt is precisely configured so that the moving speed of the step is exactly the same and the rider feels smooth.

     Unlike elevators, escalator systems can lift people up dozens of floors, but they are very suitable for short-distance transportation. This is due to the high load rate of escalators. After the elevator is full, it must wait for it to reach the designated floor and return to the elevator. On the escalator, as long as one person reaches the upper level, he will make room for others.