Axle Beam Intro
A beam axle, rigid axle or solid axle is a dependent suspension design, in which a set of wheels is connected laterally by a single beam or shaft. Beam axles were once commonly used at the rear wheels of a vehicle, but historically they have also been used as front axles in rear-wheel-drive vehicles. In most automobiles, beam axles have been replaced with front and rear independent suspensions.
Solid axle suspension characteristics: Camber change on bumps, none on rebound, large unsprung weight
With a beam axle the camber angle between the wheels is the same no matter where it is in the travel of the suspension.
A beam axle's fore & aft location is constrained by either: trailing arms, semi-trailing arms, radius rods, or leaf springs. The lateral location can be constrained by a Panhard rod, a Scott Russell linkage or a Watt's linkage, or some other arrangement, most commonly by the leaf springs. Shock absorbers and either leaf springs, coil springs, or air bags are used to control vertical movement.
The Twist-beam rear suspension is a similar suspension design, however its beam axle is able to twist thereby functioning as an anti-roll bar to control the roll motion of the body and is considered to be a semi-independent suspension design.
