Hand-carved Wooden Gears
To the best of my knowledge, the above is a Winnowing Machine, Blowing Grain from Straw.
Winnowing Mill Diagram
Wind winnowing is an agricultural method developed by ancient cultures for separating grain fromstraw. It can also be used to remove pests from stored grain. Winnowing usually followsthreshing in grain preparation. In its simplest form it involves throwing the mixture into the air so that the wind blows away the lighter chaff, while the heavier grains fall back down for recovery. Techniques included using a winnowing fan (a shaped basket shaken to raise the chaff) or using a tool (a winnowing fork or shovel) on a pile of harvested grain. (Source: https://en.wikipedia.org/wiki/Winnowing )