wheel

circular component rotating on an axle

one of six simple machines, alongside lever, wedge, screw, pulley, inclined plane

invented circa 3500 BCE in Mesopotamia, first for pottery then transport

applications: vehicles, gears, turbines, flywheels, pump impellers

converts linear force to rotational motion and back

foundational to nearly all mechanical energy transmission

the engine is a wheel-dependent system: crankshaft, camshaft, drivetrain

scaling from nanometer gears to wind turbine rotors