V-belt pulleys (also called vee belt sheaves) are devices which transmit power between axles by the use of a v-belt, a mechanical linkage with a trapezoidal cross-section. Together these devices offer a high-speed power transmission solution that is resistant to slipping and misalignment.

V-belt pulleys are solely used for transmitting power between two parallel axels. The most notable difference between a v-belt pulley and other types of pulleys (round belt, flat, etc.) would be the geometry of the groove or grooves located around the circumference of the pulley; these grooves guide and gain traction on a v-belt.

Types of V-Belt Pulleys

• Standard pulleys are pulleys that have traditional dimensions, with one or multiple grooves, which mate with classic, small-engine, and hexagonal-style v-belts.

• Companion pulleys contain integral spokes which run radially on the pulley. This produces a high strength-to-weight ratio advantageous to fractional horsepower pulleys.

• Idler pulleys are used solely as belt tensioners in many v-belt drives, but play an important part in maintaining the tension required to drive the transmission. Idlers can interact with either the wedged or flat side of the v-belt since no torque is required to be transmitted to this axle.

  Idler pulleys reduce belt service life and the efficiency of the drive but are required in transmissions where the drive needs to clear obstructions or the driven pulley does not maintain a sufficient arc of contact with the v-belt to transmit torque.

• Variable speed pulleys have a variable pitch which adjusts the driven RPM, often within a range that is represented as a percentage. These pulleys are also useful for maintaining belt tension for dynamic loads.

• Step pulleys have two or more non-adjustable grooves which have different pitches located around the same shaft. These pulleys change the speed ratio of the transmission.