A Ferris wheel is a large runner-like mechanical construction facility with a cockpit for passengers hanging on the edge of the wheel. Passengers sit on the Ferris wheel and slowly turn up, and can overlook the surrounding scenery from a high place. The most common Ferris wheel is generally found in amusement parks (or theme parks) and garden fairs. But the Ferris wheel often exists alone in other occasions, usually used as a viewing platform for activities.

According to the difference of the operating mechanism, the Ferris wheel can be divided into three types: the gravity Ferris wheel, the spokeless Ferris wheel and the Observation Wheel. The cockpit of the gravity Ferris wheel is hung on the wheel to maintain the level of the sliding shaft by gravity; while the cockpit on the observation wheel is suspended outside the wheel, which requires a more complicated mechanical structure of connecting rods, which rotates with the carriage. The position of the cockpit is adjusted synchronously to keep the cockpit in a horizontal position.
The working principle of the Ferris wheel is to use the motor to decelerate through the reducer, convert the high-speed and low-torque mechanical power into high-torque and low-speed mechanical power, and transmit it to the wheel through an intermediate mechanism such as tires that is both elastic and strong. It rotates at low speed.