The linkage system of shock absorbers and springs that are connected to vehicle’s body and its wheels is called suspension. The important function of the suspension is to keep the wheels in contact with the road. It allows the relative motion between wheels and vehicle. Suspension system serve for driving pleasure by contributing the vehicle’s braking for good active safety and handling/road holding. It will reasonably be isolated from vibrations, bumps, road noise, etc., and keep the vehicle occupants comfortable. The front and rear suspension of a car may be different.
Need of suspension and its job in the vehicle
Bumps on the road causes the vehicle’s wheels up and down perpendicularly to the surface of the road. In these situations, the vehicle frame also moves in the same direction. During the bump upward movement wheels completely lose contact with the road. Then, the gravity force the vehicle downwards which causes the wheels slam on to the surface of the road. Here, that energy absorbing system is required for the body and frame to ride undisturbed.
Vehicle dynamics is the name for the study of forces at work on moving vehicle. You need to understand some of the vehicle dynamics to understand better the suspension in your car.
The dynamics of a moving car considered by most of the automobile engineers in two perspectives. Those are ride and handling. Ride is the ability of a car to smooth out a bumpy road. Handling is the ability of a car to safely brake, corner and accelerate. These two are described by three principles. Those are cornering, road isolation and holding principles. Now we will discuss them briefly.
- One of the principles is related to the ability of the car to travel at the corner or the curved path. The goal at the curved path is to minimize the body roll. At the corners, one side of the vehicle is lowering and opposite side raise. The solution for this is weight transfer during cornering from high side to the low side of the vehicle.
- The vehicle body needs to allow the ride to travel over rough roads. So, the road shock isolating or absorbing ability of a vehicle from the passenger compartment is another important principle. Without causing undue oscillation in the vehicle, the suspension absorbs the road bumps energy and dissipates it.
- The road surface of a car changes in various directions in the straight line. For example, while braking, the weight of the car gets transferred to the front tires and while acceleration it transfers to rear tires. So, the contact with the road is required, as it is the friction between road and tires that can effect vehicle’s ability to accelerate, brake and steer. The solution for this is weight transfer from front to back and side to side.
Suspension would not be necessary when the road is perfectly flat without any irregularities. But, even newly paved highways also far from flat. They have subtle imperfections which can interact with the car’s wheels. So, suspension is an important part in your car to ride comfortably on the road.