What is Coil spring, Stabilizer bar, Torsion Bar, Rubber Spring, Air Spring, Helper Spring


Coil Spring

Its simple layout can be seen in the
figure. In this type one end of the spring is fixed with the frame, another end is fixed with the lower control arm.When the vehicle rises over a bump the spring gets compressed and it will absorb
the energy. When the vehicle gets down from the bump the spring expanded and release the energy.This type of suspension is commonly
used in Independent Suspension Systems and in Light Vehicles. It can be used in both front and rear independent suspension systems. It absorbs energy twice than that of leaf spring. Coil spring can withstand shear stress and bending stress.


1. Less noise
2. Less weight
3. Less space is enough.
4. Simple in design.


1. It can not withstand the torque and
lateral forces.

Stabilizer bar

The stabilizer bar is shown in figure
. The stabilizer bar is mounted in
between the two wheels. Stabilizer bars are part of a car’s suspension system. They are sometimes also called anti-sway bars or anti-roll bars. The main purpose is to try to keep the car’s body from “rolling” in a sharp turn. During turning, body roll occurs when more weight is placed on the outside tires and less weight is placed on the inside tires, which in turn reduces traction and vehicle control. The stabilizer bar is used to make the body of the vehicle will remain flat throughout a turn so the weight stays evenly distributed on all four tires. It is like a U shaped bar which used in front independent suspension system.

Torsion Bar

The simple layout of torsion bas is
shown in the figure. The torsion
bar is made up of hardened steel alloys.It works based on the torque principle. It is used in the independent suspension system. The one end of the torsion bar is fixed with frame and another end is
fixed with wheel arm. Wheel arm is
supported by bearing. Another end of
wheel arm is attached with the wheel
hub spindle.While travelling in bumpy road,the vibration absorption takes place by twisting. To fix the torsion bar, a minimum space is required.

Rubber Spring

The layout of rubber spring is shown in figure. Rubber springs are used in suspension systems. It absorbs more vibrations than metal springs. There are different types of rubber springs are used.

1. Compression spring
2. Compression shear spring
3. Steel reinforced spring
4. Progressive spring


1. It has the ability to store more energy than steel and iron springs.
2. It will not break suddenly like metallic springs.
3. The life of the spring is higher.
4. Rubber can withstand vibrations very well.

Air Spring

The layout of air spring is shown
in figure. Air spring gives more comfort and smooth ride to the
travellers. It provides more comfortable ride when the vehicle is unloaded and loaded conditions. They are classified into two types, namely,

1. Bellow Type
2. Piston Type

Helper Spring

This system is widely used in heavy
commercial vehicles, trucks. This helper spring does not function during light load condition. As the load increases, beyond a certain level, the spring will start functioning. The helper spring is integrated along with the Master leaf in leaf spring. Due to the increased load, the master leaf spring and helper leaf gets fully
expanded and the helper spring touches the special bracket, makes the helper leaf to function. This type of helper leaf is widely used in the rear axle.

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