Each component has a vital role to play in how well V belts perform and how long they last. Different materials and configurations can influence belt performance characteristics in specific applications.

The tensile cord is the load-carrying component of a V belt. Most V belts are made with polyester cords, although some belts are constructed with aramid or Kevlar? cords, which offer higher tensile strength, limit stretch, and can handle heavier shock loads. In a well-engineered V belt, the tensile cords and rubber body of the belt are chemically bonded to form one unit, allowing for equal load distribution and longer belt life.

Tensile cords are supported by rubber stocks, both above (over cord) and beneath (under cord). Various synthetic rubber stocks are used by different manufacturers to provide heat resistance and reduce wear. Some high-performance synthetic rubber compounds, such as ethylene, significantly extend a belt’s operating temperature range and resist hardening, cracking, and premature failure.

A well-engineered V belt will have transverse rigidity, which means a high level of rigidity across its width so that the tensile cords will transfer the load equally. At the same time, the belt must be highly flexible along its length to reduce heat and bending stresses, which in a superior belt is accomplished by parallel alignment of fibers in the rubber compound.

Adhesion gum is the element that forms a strong chemical bond between the tensile cord and the rubber stock. It bonds the belt together so that it acts as a single unit. The gum also absorbs cord stresses and avoids cord pullout.

To protect the core of the belt from destructive environmental forces such as oil, grime and heat, as well as from general wear and tear, some V belts have a fabric cover, or band ply. In a well-engineered belt, this flexible fabric is treated to form a chemical bond with the belt core materials, allowing it to withstand the stress of constant bending over time and prolonging cover life.

As described earlier, the notches in a notched V belt are designed to increase belt flexibility and reduce bending stresses, especially on small sheaves.

This article comes from powertransmission edit released