Cardan shafts facilitate the rotation of a central gear to provide motion in a limited angular range. The angular limits are imposed by the use of universal joints or constant-velocity joints on both ends of the cardan shaft. Cardan shafts are commonly used in transmissions in automobiles and four-wheel drive vehicles; they also can be found in lifting appliances such as cranes and elevators. In an automobile, the pinion is fixed to the engine's crankshaft, and rotates with it. Engaging the clutch causes the cardan shaft to rotate, which allows power from the transmission to be delivered to and transmitted by each wheel.
