At its most basic level, a belt is a looped strip of flexible material used to bind two or more rotating shafts mechanically. They can be used to transfer objects, transmit mechanical power efficiently, or monitor relative movement.
Early uses of belts
For centuries, belts, ropes, and chains have been used as traction devices. The Babylonians and Assyrians reportedly used chains for water drawing machines. These first belts were flat and operated on flat pulleys.
A Chinese text from 15 BC makes the earliest mention of a mechanical belt drive with a pulley machine. The text explains how it was set up for weavers’ shuttles to wind silk fibers onto bobbins. Approximately 1,000 years later, when the world’s first known mechanized spinning wheel was recorded as having come from China, it relied on a belt drive.
By 1430, interest in the mechanical uses of belts continued to grow, and link chains even turned up on one of Leonardo da Vinci’s sketches. Later on, the first theoretical essays on the traction mechanism (a different type of system) were published by Leonhard Euler (mathematician, 1707- 1783). The engineer Johann Albert Eytelwein (1764 – 1848) developed the Eytelwein equation in 1808 based on these essays, a concept still indispensable today for measuring frictionally engaged, non-positive drives.