A car’s suspension system is among the most significant aspects in determining the quality of the ride. Perhaps the smoothest roads are full of variations in height and surface texture. Along with the car’s natural shake as the engine runs and also the constant buffeting of air at high speeds, suspension makes driving a comfortable and safe undertaking.
Although car suspensions come in a variety of configurations, the basic elements are springs and shock absorbers. Springs provide a simple mechanical disconnect between the shocking forces sustained by the vehicle’s wheels and axles and the body of the car with the passengers inside. The majority of modern cars employ classic coil springs that are affixed vertically (or at a vertical angle) between the axle and the car’s frame. In some cases torsion bars or metal leaf springs are used. They serve the same purpose as a coil spring.
Shock absorbers provide damping of the motion experienced by the vehicle’s wheels as the move up and down over an uneven road surface. They normally use a hydraulic system to provide potential to deal with the kinetic energy manufactured by the wheels. Shock absorbers also are variable across different speeds, and therefore the more energy they are asked to absorb, the more resistance they produce. This prevents the car’s wheels firmly on the road while providing a smoother ride for the car at all points above the suspension.
The modern pairing of springs and shock absorbers evolved from earlier systems alongside the development of the automobile in general. Early car suspensions were derived from the springs used on horse-drawn carriages. As cars were designed to move at faster speeds, new suspension systems were necessary. Besides providing comfort to the passengers, excessive shaking could damage a vehicle, literally shaking it apart if the proper suspension system was not used. The first suspensions to use shock absorbers designed specifically for cars were used in the early 1900s. By 1920, British automaker Leyland was using torsion bar suspensions on some of its models. Independent suspension systems became popular in the late 1920s and early 1930s.
Since the 1930s, different suspension configurations have come and gone. However, the fundamental layout of a variety of a spring and a shock hydraulic absorber has remained the standard for all types of cars. An independent suspension system allows each one of the two wheels on a shared axle (front or rear) to move vertically independent of one another. This prevents motion on one side of the vehicle from affecting motion on the other hand and offers a smoother ride and more consistent handling. Independent suspension is especially useful during acceleration, braking, turning, and when a car’s load is unevenly distributed from side to side. Most modern cars feature independent front suspensions, where steering is performed. Other cars, especially rear-wheel drive models, may also include independent rear suspension. Cars with all four wheels suspended independently are known as “fully independent suspension”.
Independent suspension systems may feature any number of mechanical layouts and are often quite complex. For this reason, full independent suspension is found on more expensive or performance-oriented cars and trucks. Many widely used terms exist that refer to specific kinds of suspension. The “MacPherson Strut” is a simple design in which a spring and shock absorber pivot on a ball joint as the vehicle receives kinetic energy from impacts with the road.
A “double wishbone suspension” is commonly cited in automobile marketing. This term refers to a pair of wishbone-shaped arms that support the wheel spindle with a spring and/or shock absorber sandwiched in between. Double wishbone suspensions take up a great deal of space under the vehicle but allow for a large range of motion of the wheel. “I-Beam suspension” is another common term. I-Beam suspensions, also known as “twin I-Beam suspension,” is actually a seldom-used design in which a solid axle is split and rejoined in an offset pattern that produces independent front suspension. This configuration is useful in trucks carrying heavy loads, but provides little shock absorption when the vehicle is unladen.
Other Automotive News on the Web