shafting

(mechanical engineering) The cylindrical machine element used to transmit rotary motion and power from a driver to a driven element; for example, a steam turbine driving a ship's propeller.

The machine element that supports a roller and wheel so that they can perform their basic functions of rotation. Shafting, made from round metal bars of various lengths and machined to dimension the surface, is used in a great variety of shapes and applications. Because shafts carry loads and transmit power, they are subject to the stresses and strains of operating machine parts. Most shafting is rigid and carries bending loads without appreciable deflection. Some shafting is highly flexible; it is used to transmit motion around comers.

Shafts used in special ways are given specific names, although fundamentally all applications involve transmission of torque. The primary shafting connection between a wheel and a housing is an axle. A short shaft is a spindle. A short stub shaft mounted as part of a motor or engine or extending directly therefrom is a head shaft. A secondary shaft that is driven by a main shaft and from which power is supplied to a machine part is called a countershaft. See also Belt drive; Pulley.