Essay On Vehicle Uniformity

Tyres are the most important component in any vehicle and it play a commanding role in an automobile industry. Balancing and safety of the vehicle are the primary issues for automobile industry. These two parameters are highly depend on the uniformity of the tyres, no matter it is a truck, car or a bus. There are various criteria that affect tyres uniformity. Standard criteria include the parameter of Radial force variation, Lateral force variation, Conicity, Radial run-out, Lateral run-out, Top lateral run-out etc. If a vehicle tyre is not properly uniform then vehicle become imbalanced. Tyre manufacturers want to improve tyre uniformity in order to improve vehicle ride comfort. For measuring uniformity of the tyre, uniformity machine is used.
Tyre

It is the vertical force between the tyre and the road. Radial force variation is the variation in load between a tyre and the other surface when the tyre is rotated at the constant axle height with some deflection upon the surface. Radial force variations are inversely proportional to deflection and higher the deflection lower the force variation.
Radial force variation can be due to –
 Geometric variation
 Stiffness variation
 Mass variation
 Combination of any of these
Lateral force variation calculates the change in force in the lateral direction as the tyre rotates under load. Lateral force variation is a term which may be explained as a condition where the tyre steers from side to side. Lateral force variation is deflection dependent as higher the deflection higher is the force. Lateral force is signed, such that when mounted on the vehicle, the lateral force may be positive, making the vehicle pull to the left, or negative, pulling to the right.
Lateral force variation can be due to
 Belt snakng
 Belt width variation
 Tread snaking
 Snaking cushing gums
 Beads not seating a