What Does a Drive Shaft Do for an Automobile?by Andrea Stein
Cars rely on several mechanical devices to generate the power needed to operate. These components must be strong enough to handle several stressors and still transmit power. A drive shaft is an example of such a mechanical device.
A drive shaft, also called a propeller shaft or Cardan shaft, is a device used to send rotation and torque, or the force of motion, to other mechanical parts in the car. Drive shafts often connect other devices used in a drive train, which is a system used to generate and deliver power to a surface, like a road.
The main function of drive shafts is to deliver torque from one or more components of a vehicle to other components. Drive shafts often are used to carry torque from the engine and transmission to the vehicle’s other end before the torque enters the wheels. A pair of shorter drive shafts often is used to carry torque from a transaxle to the wheels.
Drive shafts must endure shear stress, or force that is applied parallel to material. Drive shafts must also endure torsion, which is the twisting of an object due to torque. Drive shafts are designed to carry these forces while not adding sufficient weight to increase the inertia, or resistance, of these forces. Drive shafts often use joints or couplings, or rods that allow a shaft to bend, which helps compensate for changes or variations in the distance between components.