What are the common types of elevators?

　　Elevators are divided into four main categories: traction and forced-drive elevators, hydraulic-drive elevators, escalators and moving walkways, and other types of elevators.

　　Traction and Forced-Drive Elevators: Traction refers to the pulling force—the mode of motion used by elevators, enabling them to move back and forth through this mechanism. Forced-drive elevators do not require an elevator machine room; instead, they are driven by chains or steel cables suspended from above, and are also known as machine-room-less elevators. Traction and forced-drive elevators include traction-driven passenger elevators, traction-driven freight elevators, and forced-drive freight elevators.

　　Hydraulic-driven elevators are elevators that use a hydraulic power source to pump oil into a cylinder, causing a piston to move in a linear motion and thereby driving the elevator car up and down. Hydraulic-driven elevators are one of the earlier types of elevators developed and are particularly well-suited for short-distance, heavy-load applications. They are widely used in low-rise buildings such as factories and parking garages and are more cost-effective compared to traction elevators.

　　Escalators and Moving Walkways: An escalator is composed of a chain-driven conveyor and a belt conveyor, arranged in a stepped configuration, and is used to transport passengers between different floors. A moving walkway, on the other hand, is a passenger-carrying device that operates horizontally or at an incline no greater than 12°; it does not have a stepped structure. Moving walkways are primarily used in high-traffic areas such as airports and exhibition halls, while escalators are mainly found in shopping malls.

　　Other types of elevators refer to elevators designed for specific purposes, such as explosion-proof elevators, fire-service elevators, and goods-only elevators. Explosion-proof elevators are equipped with explosion-proof features and are typically industrial-grade elevators that can prevent sparks and high temperatures from igniting fires. Fire-service elevators are used by firefighters during firefighting and rescue operations in the event of a fire; they feature fire-resistant designs and are relatively rare. Goods-only elevators are used exclusively for transporting goods, and no people are allowed to enter them.