Ok, I do not know if the description is technically correct. For me, these are "toothed wheels" from a old but still working sluice gate, which regulates the water inflow to a large swamp.
Gear is technically correct. This fits in nicely with the unusual farm implements I've taken photos of recently. I haven't done one in B&W yet but this is nice.
Great shot! Love the black and white for the subject too... Since you seem to be wondering, this is a worm gear drive, the spiral looking stuff below the gear wheels are the worm gears, which drive the larger gears to raise or lower the gates.
@rleidner Thank you for the english expressions. I especially asked myself if I translate it correctly. We call them literally translated "snail gear", so worm felt wrong. ;-)