Dictionary

Overrunning clutch (freewheel clutch) (Chapter 5, Chapter 10) is a part of a mechanical transmission, which prevents the transmission of torque from the driven shaft back to the drive shaft if for some reason the driven shaft starts rotating faster. The most well-known application of the overrunning clutch is in the bicycle drive. At the moment when the rider stops turning the pedals and the bike continues moving by inertia, the overrunning clutch is activated. It disconnects the wheel from the pedals, and they do not hit the feet. Sometimes overrunning clutches are used in cars with two-stroke engines, for which the "engine braking" mode is impossible due to the design features (more precisely, the  method of lubrication), which can disable them. Another widespread use of the overrunning clutch is its use in engine starters for preventing the destruction of the starter by a running engine.