Ackermann-linkage Geometry
Ackermann-linkage Geometry In parallel-set steering arms layout (Fig. 27.26A), the track-rod dimensions yi, xi andy0, x0, remain equal for all angles of turn. With the inclined arms (Fig. 27.26B and C), the inner-wheel track-rod end dimension yi, is always smaller than the outer wheel dimension y0, while negotiating a curve. On the other hand, there is very little variation between xi and x0 for small angular movements. For small steering angles about the king-pin up to say 10 degrees, there is very little difference between yi and y0 and between the inner and outer wheel turning angles. Figure 27.26B illustrates that for a 10 degrees set track rod arms if the outer wheel is turned at 20 degrees, then the corresponding inner wheel is shown to rotate 23 degrees. Similarly for the same set, for 40 degrees outer wheel turn, the inner wheel rotates 51 degrees (Fig. 27.26 C). Therefore, for a given angular movement of the stub axles, the inner-wheel track-rod arm and track-rod are more eff