A driveshaft, also known as a propeller shaft, is a rotating mechanical device used to transfer power from a motor or engine to an application requiring work. Motors and engines can produce a rotational force that causes a device or vehicle to move or be propelled, a force also known as torque. Driveshafts facilitate torque, which is produced with the help of engine-driven pistons. Driveshafts are active components of different types of mobile equipment, including automobiles, bicycles, some construction equipment, and marine equipment.
The driveshaft of mobile equipment can differ depending on the type of equipment. Automobile driveshafts typically resemble a steel tube with a u-joint, the end of which is responsible for transferring the torque and producing movement. The role of the driveshaft is to rotate at the same ratio as the transmission, or in some cases, the transfer case.
In an automobile, the driveshaft connects the transmission to the differential via the axle. The driveshaft, in turn, can transfer rotational torque to the axles where it is received by the wheels, causing the wheels to move the vehicle. Early vehicles relied on chain or belt drives instead of a driveshaft to transfer torque. The driveshaft can vary in vehicles, depending on what kind of drive it is.
RWDs typically carry a single driveshaft that is connected to the rear axle and the transmission.
4WDs have two driveshafts: one connecting to the axle and transmission as in the RWD, and another from the transfer case to the front axle; however, some newer versions of 4WD have a single driveshaft connecting the transfer case to the rear axle.