Turning Radius (Wheel Angle, Turning Angle)
The turning radius is the turning angle of the left and right front wheels during cornering. Giving the left and right different turning angles matches the centers of turning for all four wheels and increases the driving stability during cornering. For example, in the type of steering system in which the tie rods are located behind the spindles, if the left and right knuckle arms are mounted so as to be parallel with respect to the vehicle’s center line, the left and right steering angles will be equal (= ). Each wheel would turn around a different center (O1 and O2) even if they have the same radius (r1 = r2), so side slipping would be generated on one of the tires. However, if the knuckle arms are inclined with respect to the vehicle’s center line, because the left and right wheels have different turning angles ( < ), they can be set to turn with different turning radii (r1 > r2) and around the same center (O), so the proper steering angle can be obtained.
SERVICE HINT:
If the turning radius is improper, the inside or outside tire slips sideways during cornering and smooth turning is not possible. This also generates uneven wear on the side slipping tire.
