I made this animation to show how a 3 jaw drill chuck works. Commonly known as a Jacobs Chuck.
This was modeled off a $20 WARRIOR 12v Lithium-Ion 3/8" Cordless Drill/Driver from Harbor Freight but in principle all drill chucks work about the same.
Animated in SolidWorks 2020. (the front outer grip should be rotating, but I could not get it to be sliced in half and rotating at the same time due to limits with the built in animation capabilities of SolidWorks)