sentences:  Examples are sun and planet gearing (see below), cycloidal drive, automatic transmissions, and mechanical differentials.Sun and planet gearing is a method of converting reciprocating motion into rotary motion that was used in steam engines.James Watt used it on his early steam engines to get around the patent on the crank, but it also provided the advantage of increasing the flywheel speed so Watt could use a lighter flywheel.