Oldham Coupling

This is an oldham coupling used for eccentric (or shifting) drive shaft connections such as present at the Moineau pump thingy. but requires less height and space than most eccentric couplings.

I am using this coupling in my own Moineau pump derivative (in progress)
but am sure more people would like to use it for other unaligned shaft connections.
a schmidt style coupling has the same function and height