I'm posting a picture to try and keep clear. This picture is the Y axes motor and I have not started to take it off but it offered a better picture angle and the setup or application is the same.
I may not be correct in all the terms either... But my machine has shafts used as a guide and a threaded rod(s) that is used to move the router on X, Y & Z axes. The motors are attached to and turn these rods moving the router.