Download Type of Suspension

Type of Suspension:
1. Solid axle:
Summary:
The solid, or beam, axle is used in the rear suspension of many front-engined, rearwheel drive cars, and light commercial vehicles, and as the front suspension on
many heavy commercial vehicles.
The solid or beam axle provides a simple means of locating and mounting
the hub and wheel units. Together with leaf springs, it forms an effective,
non-independent suspension system.
Similarly, with coil springs.
On rear-wheel-drive vehicles, with leaf springs, the axle housing is held in
place by the springs, and no other form of location is needed.
When a vehicle accelerates from rest, the resistance of its mass causes a
torque reaction, producing a tendency for the axle housing to rotate in the
direction that is opposite to wheel rotation.
2.Dead axle
Summary
A dead axle only supports the vehicle and doesn't transmit any drive. With
a live axle, the drive is transmitted through the final drive unit and axles to
the wheels.
On front-wheel-drive vehicles, a simple beam axle can be used on the
rear, with coil spring suspension and control arms for location. This is
called a dead axle, since it only supports the vehicle and doesn’t transmit
any drive. It is also non-independent, as deflection of a wheel on one side
of the vehicle will be transferred to the other wheel.
On some vehicles, this is reduced by using a U-shaped axle beam, with a
torsion bar mounted inside it.
A lateral rod prevents lateral movement when cornering, and coil springs
provide for suspension. The torsion bar is connected between the left and
right wheel units, and deflection of the wheel on one side causes the axle
and its torsion bar to twist together.
4-wheel-drives, with rigid axles, may use leaf springs for front and rear
suspension.
3.Independent suspension
Summary
Independent suspension helps keep unsprung mass (the unsprung mass
is loosely defined as the mass between the road and the suspension
springs) low. Also, if a wheel hits an irregularity, it won't upset the opposite
wheel on the same axle. It allows wheel camber to be adjusted, or
designed into the suspension geometry.
It consists of a spring and shock absorber unit called a strut.
If the unit is on the front, the upper mounting includes a bearing to allow
the complete strut to rotate with the steering.
When the suspension is deflected, the unequal lengths allow the track of
the vehicle to be maintained near constant, but with some changes to
camber angle.
Generally, when the car leans during cornering, the inner wheel leans
outwards at the top, and the outer wheel leans inwards. This helps to
maintain maximum tire contact with the road surface.
4.Rear independent suspension
Summary
On rear-wheel drive vehicles, the suspension has to allow for the external
drive shafts.
The kind of independent suspension used on the rear of a vehicle depends
in part on whether it is front-wheel-drive, or rear-wheel-drive.
There is normally no steering on the rear wheels, so there is no need for
the bearing in the upper mounting.
On rear-wheel-drive vehicles, the suspension arrangement has to allow for
the external drive shafts to transfer the drive to the wheels.
The final drive assembly is normally fixed to a cross-member, and since it
must absorb the torque reaction, it must be secure. Drive shafts, either
with conventional or constant velocity joints, transmit the drive to the
wheels.
In some designs, the wheel units are located at the outer ends of semitrailing arms. The arms are attached to their cross-member pivot-points by
rubber bushes, and constant-velocity joints are used at each end of the
external drive shafts.
5. Rear-wheel drive independent suspension
Summary
On rear-wheel drive vehicles with independent suspension, the final drive
unit is fixed to the vehicle frame. Drive is transmitted to each wheel by
external drive shafts.
Suspension is normally by coil springs.
With a single arm, an angled bracing strut is needed.it prevents forward
movement, and rearward movement. Similarly, during acceleration.
The rear suspension on front-wheel-drive vehicles must maintain
alignment of the rear wheels with the front, and also with the frame.
On vehicles with 4-wheel steering, the rear suspension must also allow for
swiveling of the rear wheels.
External forces, such as kerb impact or a collision, can damage control
arms or linkages and move the wheel units from their correct position.
This can make a vehicle pull to one side, cause abnormal wear in the tires,
and make the vehicle difficult to drive.
6.Adaptive air suspension
Summary:
Adaptive air suspension is an electronically controlled air suspension
system at all four wheels with a continuously adaptive damping system.
Adaptive air suspension is an electronically controlled air suspension
system at all four wheels with a continuously adaptive damping system.
It combines sporty handling with a high level of ride comfort.
The information obtained from sensors on the axles and acceleration
sensors on the body is evaluated in the adaptive air suspension's central
control unit. This computer can control the adjustment of the individual
shock absorbers in milliseconds, depending on driving situation.
Adaptive air suspension also offers the advantages of:



The vehicle's suspension height remaining constant irrespective of
the load it is carrying;
Adjustable dampening characteristics and ride height using a single
process, via the manufacturers installed ‘Car Performance’ menu;
and, generally, an ability for the driver to influence the suspension
characteristics, and thus the operating dynamics, as individually
preferred.
Front Suspension Type and component
1.Strut suspension
Summary
In strut suspension a telescopic type shock absorber is contained inside the
strut with the coil spring mounted over the strut inside the suspension
tower. The control arm mount is fixed (or 'held in place') in the vehicle
configuration, by bushes.
For the front steerable suspension, the strut’s upper mounting is bushed,
or bearing-mounted, to allow for the steering movement.
The control arm mount is fixed (or ‘held in place’) in the vehicle
configuration, by bushes.
The lower control arm is attached to the vehicle body and holds in place
the strut, brake assembly, and drive shafts.
2.Short/long arm suspension
Summary
In short/long arm suspension the lower control arm pivots on bushes
that twist on the lower control arm pin, which is bolted to the crossmember of the vehicle. The lower control arm is longer than the upper
control arm.
The shock absorber is located inside the coil spring, and is a direct
acting telescopic type shock absorber.
The coil spring is mounted between the upper and lower control
arms.
The lower control arm is longer than the upper control arm. It moves
up and down to accommodate movement in the suspension. These
are stop and rebound rubbers. They are used to prevent direct metalto-metal contact, if the suspension should reach its maximum limit of
travel.
The upper control arm pivots on bushes. These bushes twist on the
upper control arm pin, which is bolted to the vehicle’s cross-member.
3.Torsion bar suspension
Summary
The torsion bar supports the vehicle load and twists around its center to
provide the springing action. The spring rate depends upon the length of
the bar. The shorter and thicker the bar, the stiffer its spring rate.
The torsion bar extends from the front suspension to a point towards
the rear of the vehicle
In this application, the other end of the torsion bar is located at the
front suspension. It is the front pivoting point for the suspension.
The system also has an upper control arm bush that is attached to
the upper part of the cross-member. The lower ball joint is attached
to the lower control arm and allows the steering knuckle to rotate as
the steering.
Rear Suspension Type and component
1.Rigid axle leaf spring suspension
Summary
The leaf spring is usually made up of a number of leaves of different length.
The top, or longest leaf, is normally referred to as the main leaf.
The front of the leaf spring is attached to the chassis at the rigid spring
hanger. This spring eye is bushed with either rubber bushes or, in the case
of heavy vehicles, steel bushes.
The axle housing is rigid between each road wheel. This means that any
deflection to one side is transmitted to the other side.
The top of the shock absorber is attached to the chassis, and to the spring
pad at the bottom. It is a direct-acting shock absorber.
Leaf springs are usually made of tempered steel. They hold the axle in
position, both laterally and longitudinally.
2.Rigid axle coil spring suspension
Summary
The telescopic-type shock absorber is attached to the axle at the bottom
and to the chassis at the top. The coil spring is mounted between the axle
housing and the vehicle body.
The shock absorber is attached to the axle at the bottom and to the
chassis at the top. It is a direct-acting, telescopic-type shock absorber.
The coil spring is mounted between the axle housing and the vehicle body.
The axle housing is rigid between each road wheel. This means that any
deflection to one side is transmitted to the other side. In other coil-spring
rear suspension designs, this is achieved with an angled panhard rod.
The upper trailing arm provides the additional control for the longitudinal
movement. These trailing arms are mounted in rubber bushes.
3.Independent type suspension
Summary
The trailing arm is attached to the chassis at a rigid cross-member pivot
point. This pivot point is fitted with rubber bushes. The fixing frame is
attached to the vehicle body. The frame supports the differential unit and its
housing.
In this application the shock absorber is attached to the chassis at the top,
and to the axle at the bottom. It is a direct-acting, telescopic-type shock
absorber.
The coil spring is mounted between the axle housing and the vehicle body.
The lower trailing arm assists in maintaining the longitudinal and lateral
position of the housing.
In addition, the drive torque is transmitted through this arm to the vehicle
body.
The trailing arm is attached to the chassis at a rigid cross-member pivot
point. This pivot point is fitted with rubber bushes.
The fixing frame is attached to the vehicle body. The frame supports the
differential unit .