All the parts which perform the function of isolating the automobile from the road shocks are collectively called a suspension system.

The energy of road shocks causes a spring to oscillate, and these oscillations are restricted to a reasonable level by the damper, which is commonly called as SHOCK ABSORBER.

STEEL SPRINGS (a) leaf springs (b) tapered leaf spring (c) coil spring (d) torsion bar RUBBER SPRINGS (a) compression springs (b) compression- shear spring (c) steel –reinforced spring (d) progressive spring (e) face- shear spring (f) torsional shear spring

PLASTIC SPRING

AIR SPRING

HYDRAULIC SPRING

Rubber springs Leaf springs

Coil springs

Torsion bars

Hydraulic shock absorbers

Gas-pressurized shock absorbers

It is the ratio of the shock absorber resistance to jounce(upward movement) and to rebound(downward movement).

For ex. 50/50 ratio would mean equal resistance to jounce and rebound.

Most shock absorbers are designed for 50/50 ratio only.

This ratio only describes what % of the shock absorber’s total resistance is in compression and what % is in extension.

These semi elliptic springs are widely used for rear suspension

The lengthiest blade (master leaf) has eye on its ends

The spring is supperted on the axle, front or rear by means of U- bolt

Fiberglass Lightweigh

t Compact High

tension

Taperlite leaf springs have following advantages over conventional leaf springs

light weight nearly 60% of conventional spring

They occupy less space The stresses are lower and more uniform

compared to the conventional springs,thus having more life,

In single taper leaf spring there is no collection of moisture between the leaves and hence no freeting fatigue.

The coil springs are used mainly with independent suspension.

The energy stored per unit volume is almost double in case of coil springs than leaf springs.

Coil springs do not have noise problems, nor do they have static friction causing harshness of ride.

Torsion bar is simply a rod acting in torsion and taking shear stresses only

These are made of heat-treated alloy spring steel

Torsion bars is often used with the independent suspension

Torsion bar spring is lighter as compared to leaf spring.

The advantages of using rubber as a means of suspension are-

It can store greater energy per unit weight than steel.

The rubber has excellent vibration damping properties

Rubber is more reliable. A rubber suspension cannot suddenly fail like metal springs.

The number of bearings is reduced considerably for the rubber suspension system.which means longer life

Rubber springs

FRONT WHEEL(DEAD AXLE) INDEPENDENT SUSPENSION

a)Wishbone type or parallel link typeb)Mac Pherson strut typec) Vertical guide typed)Trailing link typee)Swinging half axle type REAR WHEEL(LIVE AXLE) INDEPENDENT

SUSPENSION

It consists of upper and a lower wishbone arms pivoted to the frame member.

The spring is placed in between the lower wishbone and the underside of cross member.

The upper arms are shorter in length than the lower arms.

These helps to keeps the wheel track constant, thereby avoiding the tyre scrub thus minimizing tyre wear.

Torque loads create bushing and control arm deflection during braking, corning, acceleration and deceleration.

This causes a toe change to enhance straight line stability

Toe change during corning leads to quicker and more responsive steering

In this type only lower wishbone is used. A strut containing shock absorber and

the spring carries also the stub axle on which the wheel is mounted.

This system is simpler than double wishbone type and is also lighter, keeping the unsprung weight lower.

This type of suspension gives the maximum room in the engine compartment and is commonly used on front wheel drive cars.

A volute spring is a compression spring in the form of a cone

Under compression the coils slide over each other, affording longer travel.

This suspension was first introduced in the US army tanks.

In this type of suspension a coil spring is attached to the trailing link which itself is attached to the shaft carrying the wheel hub.

Trailing-arm and multilink suspension designs are much more commonly used for the rear wheels of a vehicle where they can allow for a flatter floor and more cargo room.

 It is used on the front axle

Leaf springs control side sway A large amount of un-sprung weight Take up a lot of space

The upper control arms control lateral movement (side movement)

The lower control arms control differential torque (wind up)

Used on many sports cars.

Handles cornering loads

better

NoteHydraulic

mount

Superior noise and vibration dampenin

g

The axle assemble twists, gives semi-independent effect

The axle assembly acts as a sway bar Track bar controls side movement

Caster & Toe adjustable

Improved ride quality, steering control, tire life, & traction

Lighter

Toe is adjustable

Camber is not