STEERING AND FRONT AXLE
The Ackermann Principle If the instantaneous centre of the two front wheels do not coincide with the instantaneous centre of the back wheels, the skidding on the front or back wheels will definitely take place, which will cause more wear and tear of the tyres. Thus, the condition for correct steering is that all the four wheels must turn about the same instantaneous centre. The axis of the inner wheel makes a larger turning angle than the angle subtended by the axis of outer wheel. To achieve true rolling for a four wheeled vehicle moving on a curved track, the lines drawn through each of the four wheel axes must intersect at the instantaneous centre (Fig). The actual position the instantaneous centre constantly changes due to the alternation of the front wheel angular positions to correct the steered vehicle’s path. Since both rear wheels are fixed on the same axis but the front wheel axles are independent of each other , the instantaneous centres lies somewhere along an imagi