Engineering a notched belt is a balancing act among flexibility, tensile cord support, and stress distribution. Precisely formed and spaced notches help to evenly distribute stress forces as the belt bends, thereby helping to prevent undercord cracking and extending belt life.

Like their synchronous belt cousins, V-belts have undergone tremendous technological development since their invention by John Gates in 1917. New synthetic rubber substances, cover materials, construction methods, tensile cord advancements, and cross-section profiles have led to an often confusing array of V-belts that are extremely application particular and deliver vastly different levels of performance.
Unlike toned belts, which rely solely on friction and will track and slip off pulleys, V-belts possess sidewalls that fit into corresponding sheave grooves, offering additional surface and greater balance. As belts operate, belt stress applies a wedging force perpendicular with their tops, pushing their sidewalls against the sides of the sheave grooves, which multiplies frictional forces that permit the drive to transmit higher loads. How a V-belt fits in to the groove of the sheave while working under tension impacts its performance.
V-belts are manufactured from rubber or synthetic rubber stocks, so they have the versatility to bend around the sheaves in drive systems. Fabric materials of varied types may cover the share material to supply a layer of safety and reinforcement.
V-belts are manufactured in various industry standard cross-sections, or profiles
The v belt china classical V-belt profile dates back to industry standards created in the 1930s. Belts manufactured with this profile can be found in many sizes (A, B, C, D, Electronic) and lengths, and so are widely used to replace V-belts in old, existing applications.
They are used to replace belts on commercial machinery manufactured in other areas of the world.
All the V-belt types noted over are usually available from producers in “notched” or “cogged” variations. Notches reduce bending stress, enabling the belt to wrap easier around little diameter pulleys and allowing better high temperature dissipation. Excessive heat is a major contributor to premature belt failing.

Wrapped belts have a higher level of resistance to oils and intense temperatures. They can be used as friction clutches during set up.
Raw edge type v-belts are more efficient, generate less heat, enable smaller pulley diameters, boost power ratings, and provide longer life.
V-belts appear to be relatively benign and simple pieces of equipment. Just measure the best width and circumference, find another belt with the same measurements, and slap it on the drive. There’s only 1 problem: that strategy is about as wrong as possible get.