Belt transmission is a mechanical transmission that uses a flexible belt tensioned on a pulley to perform movement or power transmission. Base on different transmission principles, there are friction-type belt transmissions and synchronous belt transmissions. According to different uses, there are transmission belts for general industrial use, automobiles, agricultural machinery and household appliances.

About the friction-type belt transmissions, the most widely used is the V-belt drive.

The cross section of the V-belt is an isosceles trapezoid, and the pulleys are also made into corresponding grooves. During transmission, the V-belt only contacts the two sides of the groove. It means that the two sides of the V-belt are working surfaces, and the bottom surface of the belt does not contact the pulley.

According to the friction principle of the groove surface, under the same tension, the V-belt drive can produce greater friction than the flat belt drive. Therefore, the V-belt has a strong transmission capacity and a more compact structure.

Compared with flat transmission belts, V-belt has the advantages of easy installation, small footprint, high transmission efficiency and low noise, and it occupies an important position in the entire transmission field.

And other type of belt transmission is called synchronous belt transmissions. The synchronous belt transmissions driven by the meshing of the teeth on the belt and the pulley.

It transmits movement through the meshing of transverse teeth distributed equidistantly on the inner surface of the transmission belt and corresponding tooth grooves on the pulley.

Compared with friction-type belt transmission, there is no relative sliding between the pulley and the transmission belt of the synchronous belt transmission, which can ensure a strict transmission ratio. However, the synchronous belt drive requires high center distance and dimensional stability.