V-belts transmit torque between shafts. The belt should not be in contact with the bottom of the belt pulley groove, but with its sides only. Considering the fact that a V-belt transmits torque at a relatively low tension, the V-belt drive has certain qualities, such as a higher efficiency compared to a flat belt drive, or improved safety of the drive in cases where there is small belt pulley contact. It also allows the belt to slip in cases of high shock load.
