Introduction:
In 1949, Earle S. MacPherson designed the McPherson strut construction, which is still the most commonly used front suspension today. The first car on which the McPherson suspension was fitted was the Ford Vadette.
Characteristics of the McPherson suspension:
The major advantage of the McPherson suspension is that the spring and shock absorber are combined. This saves a lot of space and is also easy to design when developing the car. As a result, production costs are also low.
The McPherson suspension is a further development of the suspension with two transversely mounted control arms (also called a double wishbone construction). The upper control arm is replaced by the piston rod of the shock absorber, which now also absorbs the lateral forces. Therefore, in the event of a collision against the wheel (by another vehicle or when driving against a kerb is hit), damage usually occurs directly to the piston rod. It deforms very quickly and is then bent. The complete shock absorber must then be replaced.
The McPherson suspension is always used at the front of the car. Struts are sometimes also used on the rear axle, but these are not of the McPherson type. For the rear suspension, the coil springs and shock absorbers are often implemented separately.
The operation of a coil spring is not based on bending, as you might first think, but on torsion (twisting). When the spring is compressed, the helical bar will be twisted.
On top of the strut is the top bearing. The top bearing makes steering movements possible. The strut is often attached with bolted connections to the bodywork under the bonnet. This is therefore a fixed point. The top bearing, located beneath it, ensures that the complete strut can rotate smoothly relative to the upper fixed point. This load-bearing system with a pivot point and a top bearing is called the McPherson system.
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