Belt span is defined as the?

Belt span refers to the specific distance along the belt that is engaged with the sheaves (pulleys). This measurement is particularly important for understanding how the belt interacts with the sheave system. As it pertains to the mechanics of power transmission, the span defines the effective portion of the belt that transmits power, ensuring that it has adequate contact with the sheaves to function properly.

When considering the context of mechanical systems, grasping the significance of the belt span is vital. A properly defined belt span can influence factors such as efficiency, wear, and the overall performance of the mechanical system. Each individual sheave's geometry, such as its diameter and width, can also affect how the belt engages with it, which adds further importance to accurately measuring the span.

The other options pertain to different aspects of the belt and sheave system, such as the total length of the belt or other physical characteristics, but they do not specifically define the concept of "belt span" as it directly relates to the interaction points between the belt and the sheaves.