Impeller Drive shaft Types
In mans search for a better mouse trap, he often does a little experimentation. Each has it's flaw and it's strong point. And when the next guy sits down to top the last guy, you end up with another mouse trap, whether you thought you needed one or not.. The same holds true for any machinery, so, here's a small sample of  shaft  ends that have been used over the years and what the name for it is...

Slotted Shaft Pin Drive

Through Hole Pin Drive

Key Drive, Also comes in Taper Shaft Key Drive

Tri-Dent Drive also available in
Square Drive

Single Flat Drive

Double Flat Drive

Ding Drive (Key-way) Also comes
in Taper Shaft

Spline Drive

Note: Keep in mind that there have been a mix of several of these in one application similar to the idea of a Splined/Key-way Drive  and Splined/Flat Drive.