Vehicle Suspension Systems: Springs, Shocks, and More
Vehicle Suspension Systems
Springs
Formed by a cylindrical rod (10 to 14mm), made of special steel and helicoidal in shape. They exert a force; when the length decreases, the force increases. Upon cessation of force, they return to their initial state. They have a poor ability to store energy, so they need a damper to absorb the spring’s reaction.
Crossbows
Constructed of elastic steel, they have a weak performance in elasticity. They are united towards a bolt and clamps.
Torsion Bars
Solid bars made of elastic material. The ends are shaped with flutes that anchor one end to the chassis and the other to the suspension arm. When the arm rotates, it causes a twisting motion in the bar.
Shocks (Dampers)
Their operation is based on a piston gliding within a cylinder. The volume of the rod is added or subtracted to compensate for volume differences. They are filled with gas at the top. The cylinder is mounted to the chassis, and the piston to the suspension arm. Characteristics: They must have adequate fluidity and viscosity, which should be less variable with temperature changes.
Double Acting Shocks
These consist of valves; half work on expansion, and the other half on compression. The advantage is that by varying the diameter of one or the other, different effects can be achieved in each direction.
Braces
These are steel arms placed between the vehicle’s structure and the suspension system through elastic joints. Their function is to absorb longitudinal displacements during braking and acceleration by joining the chassis lengthwise.
Stabilizer Bars
An elastic steel bar whose function is to offset the efforts of one wheel on the other on the same axis. Assembly depends on the type of suspension:
- Independent: Transversely mounted.
- Other cases: Through a link suspension at the shaft connection.
- Rigid: Transversely coupled to the shaft at one end and the chassis on the other.
Suspension Arms
Their function is to connect the frame and wheels and also serve as support for the spring and damper.
Transverse Arms
May be formed by one or more arms. Depending on the type, any spring suspension can be used, accompanied by a shock absorber.
Longitudinal Arms
Only for rear mounting, with two options: trailing and semi-trailing arms.
Rigid Suspension
The two wheels are mounted on a single axis. The movement of one wheel affects the other. The most significant drawback is that when a wheel goes over an obstacle, the bodywork does not maintain a horizontal position.
Semi-Rigid Suspension (De Dion Axle)
The wheels are connected by articulated shafts to the differential and a shaft fixed to the chassis.
Delta-Link Axle
This consists of cross arms tied together by elastic bearings.
Independent Suspension
The objective is to improve comfort and stability.
Swing Axle
A joint drive shaft and axle with two joints. This suspension is not used in the guideline because the axis causes irregular tire wear.
Trailing Arms
The arms are joined at one end to the body and the other to the wheel. They use torsion bar springs and elastic elements.
McPherson Strut
Very commonly used on the front axle. It has a swinging arm attached at one end to the frame by bearings and partly to the knuckle through a patella.
Deformable Parallelogram Suspension
Among the most used, both front and rear. It consists of two triangle-shaped arms attached to the frame by two bearings, joining the knuckle with ball joints.
Multi-Link Suspension
Has several wishbones fixed by bearings. Utilizing rear wheels allows for self-direction.