Rotary mechanisms are systems that convert linear motion into rotational motion or vice versa. They are commonly found in various machines and devices, such as engines, gears, and turbines. These mechanisms often utilize components like shafts, bearings, and pulleys to facilitate smooth movement and transfer of energy. One of the simplest examples of a rotary mechanism is a wheel on a bicycle. When the rider pedals, the linear motion of the legs is transformed into the rotational motion of the wheels, propelling the bicycle forward. Other applications include electric motors, which use rotary mechanisms to drive various appliances and tools.