Engineering a notched belt can be a balancing act among versatility, tensile cord support, and tension distribution. Precisely shaped and spaced notches help evenly distribute tension forces as the belt bends, thereby helping to prevent undercord cracking and extending belt lifestyle.
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 selection of V-belts that are extremely application specific and deliver vastly different degrees of performance.
Unlike smooth belts, which rely solely on friction and will track and slip off pulleys, V-belts possess sidewalls that match corresponding sheave grooves, offering additional surface and greater stability. As belts operate, belt tension applies a wedging push perpendicular to 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 operating under stress 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 kinds may cover the stock material to provide a layer of safety and reinforcement.
V-belts are manufactured in various industry regular cross-sections, or profiles
The classical V-belt V Belt profile goes back to industry standards created in the 1930s. Belts manufactured with this profile come in a number of 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 industrial machinery manufactured in other areas of the world.
All the V-belt types noted over are typically available from manufacturers in “notched” or “cogged” versions. Notches reduce bending stress, allowing the belt to wrap easier around little diameter pulleys and enabling better warmth dissipation. Excessive high temperature is a significant contributor to premature belt failing.
Wrapped belts have an increased resistance to oils and severe temperatures. They can be utilized as friction clutches during set up.
Raw edge type v-belts are more efficient, generate less heat, allow for smaller pulley diameters, increase power ratings, and offer longer life.
V-belts look like relatively benign and simple devices. Just measure the top width and circumference, discover another belt with the same measurements, and slap it on the drive. There’s only 1 problem: that strategy is approximately as wrong as you can get.