What is the difference between sway bar and anti roll bars?
Anti roll bars are also called anti-sway bars and they are used to reduce the rolling of the vehicle while describing acute or sharp turns. It is installed in a vehicle to minimize the influence of the wheels on the right over the wheels on the left of the vehicle.
From this, it is clear that anti roll bars are the exact opposite of the sway bars. Actually, sway bars were installed in the vehicles, to get both the wheels influenced by each other, while taking a turn. Sway bars are no longer used because they were not so efficient in preventing the rolling of the vehicle.
The anti roll bars perform more efficiently than sway bars. Thus, increasing the stability of the vehicle and by controlling the understeer and oversteer characteristics of the vehicle.
An anti-roll bar performs it's function by the virtue of one of the property of it's material, i.e, Torsional rigidity. While describing a turn,as the inside wheels go up, an anti-roll bar tends the outside wheels to go up, so that the relative movements of the two wheels gets neutralized. This happens due the torsional stiffness of the material of the bar.
The stiffness of the anti roll bar may also change the slip angle of the vehicle. The more is the stiffness of the vehicle, the less are the slip angles due to increased traction.
One can also install an anti roll bar with variable stiffness, so that the slip angles may be changed according to driving conditions.