Car Suspension

A suspension system comprises springs, shock absorbers and linkages. This suspension connects an automobile to its wheels. The suspension systems not only help in the proper functioning of the car's handling and braking, but also keep vehicle occupants comfortable and make your drive smooth and pleasant. It also protects the vehicle from wear and tear.

To know about the suspension system, one needs to know about the spring rate or suspension rate. Various spring types are used for different vehicles. In case of heavier suspension loads, the spring rate is higher and vice versa. Spring rate is measured as a ratio used to measure how resistant a spring is to being compressed or expanded during the spring's deflection.

Besides spring rate, one needs to take in account the wheel rate. Wheel rate is the effective spring rate when measured at the wheel. It is generally equal to or considerably less than the spring rate.

There are two types of suspension systems- dependent and independent. A dependent suspension comprises a beam that holds wheels parallel to each other and perpendicular to the axle. An independent suspension helps in the rising and falling movement of the wheels. There is also a semi-dependent suspension where the motion of one wheel affects the position of the other but they are not rigidly attached to each other.

The dependent suspension includes Trailing arms, Satchell link, Panhard rod, Watt's linkage, WOBLink and Mumford linkage. The independent suspensions includes Swing axle, Sliding pillar, MacPherson strut/Chapman strut, Upper and lower A-arm (double wishbone), multi-link suspension, semi-trailing arm suspension, swinging arm and leaf springs.

The Military AFVs including tanks require a special type of suspension system. These suspension systems weigh more than seventy tons and can function at high speed over rough ground. The torsion-bar suspension sometimes includes shock absorbers.