Engineering a notched belt can be a balancing act between versatility, tensile cord support, and tension distribution. Precisely formed and spaced notches help evenly distribute stress forces as the belt bends, thereby helping to prevent undercord cracking and extending belt existence.
Like their synchronous belt cousins, V-belts have undergone tremendous technological development since their invention by John Gates in 1917. New synthetic rubber compounds, cover materials, construction strategies, 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.
V Belt Unlike smooth belts, which rely solely on friction and can track and slip off pulleys, V-belts possess sidewalls that match corresponding sheave grooves, providing additional surface and greater balance. As belts operate, belt pressure applies a wedging force perpendicular to their tops, pressing their sidewalls against 
the sides of the sheave grooves, which multiplies frictional forces that allow the drive to transmit higher loads. How a V-belt fits into the groove of the sheave while working under pressure impacts its performance.
V-belts are produced from rubber or synthetic rubber stocks, so they possess the versatility to bend around the sheaves in drive systems. Fabric materials of varied types may cover the stock material to provide a layer of safety and reinforcement.
V-belts are manufactured in a variety of industry regular cross-sections, or profiles
The classical V-belt profile dates back to industry standards created in the 1930s. Belts manufactured with this profile can be found in several sizes (A, B, C, D, Electronic) and lengths, and so are widely used to replace V-belts in older, 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 manufacturers in “notched” or “cogged” versions. Notches reduce bending stress, allowing the belt to wrap easier around small diameter pulleys and permitting better temperature dissipation. Excessive temperature is a significant contributor to premature belt failure.
Wrapped belts have a higher resistance to oils and severe temperature ranges. They can be utilized as friction clutches during set up.
Raw edge type v-belts are better, generate less heat, enable smaller pulley diameters, increase power ratings, and offer longer life.
V-belts look like relatively benign and simple pieces of equipment. Just measure the top width and circumference, discover another belt with the same measurements, and slap it on the drive. There’s only one problem: that approach is about as wrong as possible get.
