What does a gear train consist of?

A gear train consists exclusively of gears that are connected to each other in a specific arrangement to transmit torque and rotational motion from one gear to another. In a gear train, each gear is typically mounted on a shaft, and when one gear turns, it causes the adjacent gear to turn in the opposite direction. This system allows for modifications to speed, torque, and direction of rotational motion.

The focus on gears is fundamental because they are the primary components that achieve the desired mechanical advantage in many machines. Various applications exist for gear trains, including in clocks, vehicles, and machinery, where the precise interaction between the teeth of the gears facilitates efficient power transmission.

Other components like belts, chains, or pulleys might be utilized in different mechanical systems for power transmission, but they do not fit the strict definition of a gear train as they do not involve interlocking gears. Thus, options that include such elements are not classified as gear trains.