Round Belt Pulleys

Round belt pulleys are mechanical devices which transmit rotational motion around an axle. They are used to lift loads or to apply/transmit power.

The round belt pulley accommodates a belt, cable, or rope in a groove around the circumference of the device to guide the drive element. Round belt pulleys are very efficient (approx. 95%), they can produce a mechanical advantage, and they are recognized as one of the six simple machines.

Round Belt Pulley Operation

Power Transmission

In many incarnations, a pulley transmission greatly resembles a roller chain drive. Most transmission applications utilize a belt to transmit energy between pulleys. A pulley transmission offers several advantages over roller chains drives. Not only can pulleys account for axial misalignment, but axles can be perpendicular or reside at any other angle. It's also common to employ a pulley transmission in a crossover drive to reverse the direction of the receiving pulley.

Round Belt Pulley Specifications

Pulley geometry is represented in metric and avoirdupois units, but there is no other structural or design difference between the types. Other considerations for integrating pulleys include:

• Belt dimensions: The size range of belt/line diameters that the pulley can contain between its grooves, as well as the appropriate length of the belt when accounting for the center distance of the pulleys, the pulley diameters, and the stretch of the belt. Manufacturer Durabelt has developed a belt calculator to assist in these considerations.
• Pulley diameter: Based on the application, axle distances, HP transmitted, and mechanical advantage, procuring round belt pulleys is an arduous decision. A pulley-sizing calculator has been established to determine the optimal diameters for pulleys based on the aforementioned factors.
• Pitch diameter: Pitch or datum diameter for a pulley is the diameter of the line of action. Typically it is at or near the center of the circular pulley groove.