V-belt drives transmit power through friction between the belt and pulley. With efficiencies ranging from 95 to 98 percent at installation, these drives use energy more efficiently than roller chain drives, and somewhat less efficiently than synchronous belt drives. V-belt drives are an industry standard, offering a wide range of sizes at relatively low cost, along with ease of installation and quiet operation. 

V-belts are manufactured in a variety of materials, cross-sections and reinforcement materials, and are often used singly, in matched sets or in joined configurations. They are well-suited for severe duty applications, such as those involving shock loads and high starting loads. Standard V-belt drives operate best in applications of 500 RPM or greater, speed ratios of up to 6:1, and within an operating temperature range of minus-40 to 130 degrees Fahrenheit. Because V-belts slip when overloaded, they help protect more expensive equipment from load surges. They also allow flexibility in the positioning of the motor and the load.

In a suitable application, the service life of a properly installed and maintained V-belt drive ranges from 20,000 to 25,000 hours. The components of a simple V-belt drive are relatively inexpensive to purchase, install, replace and maintain. After they are installed properly and tensioned to the belt manufacturer’s recommended values, these drives require very little service, except for retensioning during the normal maintenance schedule. Due to belt slippage, they lose up to 5 percent of their efficiency after installation. V-belts stretch as they wear, making slippage worse, which can decrease efficiency by as much as 10 percent unless corrected by periodic retensioning. Cogged or notched V-belts can increase efficiency by 2 percent over standard designs.