Vbelts

V-belts are power transmission belts with a trapezoidal cross-section that run in grooved pulleys. They transmit torque through friction and a wedge action, allowing relatively high power in a compact drive. The belt’s shape causes it to wedge into the pulley groove as tension is applied, increasing friction and preventing slipping under load.

Construction and materials: A V-belt typically consists of a rubber or elastomer compound reinforced with fabric plies and longitudinal cords made of polyester, fiberglass, or sometimes steel. The outer surface provides traction, while the inner surface forms the belt’s wedge profile. Belts are joined into a continuous loop by splicing. Common belt profiles are categorized as classical (A, B, C, D, E) and narrow (SPZ, SPA, SPB, SPC), with each profile designed for different power ranges and pulley sizes. Modern belts often use synthetic cords to improve strength and longevity.

Operation and maintenance: V-belts rely on correctly tensioned, aligned pulleys and a fixed center distance. Proper tension minimizes slip and wear, while alignment prevents edge wear and belt heat. Regular inspection for cracking, glazing, fraying, oil contamination, or missing cords is important. Replacement is typically done in sets to maintain balanced drive performance, and lubricants or belt dressings are generally not recommended on active belts.

Applications and evolution: V-belts are commonly used in automotive accessory drives, industrial machinery, conveyors, compressors, and pumps. They remain a cost-effective, simple solution for medium-power drives, though advances in timing belts and other non-slip belt systems have expanded available options for high-speed or precision applications.