A propeller shaft connects a
propeller to an engine. It is also the British English term for the
driveshaft which connects an automobile gearbox to a rear
differential. It is commonly referred to as a "prop-shaft".
The propeller shaft assembly consists of a propeller shaft, a slip
joint and one or more universal joints. Where the engine and axles
are separated from each other, as on four-wheel-drive and
rear-wheel-drive vehicles, it is the propeller shaft that serves to
transmit the drive force generated by the engine to the axles. For
its usage, the optimal shaft is a short, bar-like product. The
longer the bar, the more liable it is to sag, and sagging is further
promoted when rotation is applied. Sagging causes vibration and
results in an increase in noise, to such an extent that the shaft is
likely to break when the critical speed is exceeded. The propeller
shaft is naturally designed not to break when used within the
service limits expected of use. In addition, it is designed to
suppress vibrations arising from a wide range of causes.
The propeller shaft should always be connected with a flexible
coupling like you can find in many rear wheel driven vehicle to
eliminate all the vibrations.
