Ratchet Wheel

On a mechanical movement, the ratchet wheel is located above the mainspring barrel. This wheel is attached to the barrel’s arbor via a single screw. It is responsible for transferring energy to wind/coil the mainspring. The energy is stored (power reserve) and released (time keeping). The stored energy is a result of either manually winding the movement via the crown, or from the spinning of the rotor on the automatic wind unit.