Belt Constraint, or something similar to that?

You know how car engine have belts? (example) I built a engine and I need a belt, but I didn’t find anything. If there’s no way possible, should I stick to cogwheels?

To put it simply: Blender or (a one that I don’t recommend doing) a lot of small parts that are rotated.

You can achieve the look of a belt (it wont be functional)… by using beams.

Like this: