What would cause a belt to turn over in a sheave?

A belt turning over in a sheave is primarily caused by misalignment. When the sheave and the belt are not properly aligned, the belt can sit unevenly on the sheave. This misalignment can happen due to improper installation, wear and tear on components, or a shift in the physical layout of the drive system. As the belt runs, the misalignment causes it to ride at an incorrect angle or position on the sheave, leading to it flipping over.

Misalignment can result from various factors, including improper mounting of the sheaves, or if the shafts are not parallel. Ensuring alignment is crucial for the smooth operation of drive systems, as it helps maintain the intended path of the belt, thereby preventing it from turning over or derailing. Properly aligned machinery helps reduce wear on both belts and sheaves, leading to an extended operational lifespan.

Although the other options may affect the performance or integrity of the belt and sheaves, they are not the primary reasons for a belt turning over in a sheave.