Flywheel

The Flywheel is a large heavy wheel driven by the Crank shaft and Piston . It is used to maintain the momentum of the engine. This is necessary particularly on a single Cylinder Steam engine as the drive from the Piston is only available on part of the revolution of the Crank shaft. In operation the momentum of the flywheel pushes the Piston back down the Cylinder to begin the cycle again. On a dual Cylinder engine it is not so necessary as drive is available in two parts of the Crank shaft revolution. A flywheel is still use on multi Cylinder engines to provide a smooth run.