rotor
rotating part of an mechanical or electromechanical device
impeller
rotor used to increase (or decrease in case of turbines) the pressure and flow of a fluid or gas
stir bar
small, coated magnet used for magnetic stirring in the laboratory
rotor
non-stationary part of a rotary electric motor
hard disk drive platter
circular disk on which magnetic data is stored in a hard disk drive
shaft
rotating machine element used to transmit power from one part to another
helicopter rotor
rotary wings and control system that generates the lift and thrust for a helicopter
tail rotor
small tail-mounted helicopter rotor