SUSPENSION SYSTEM AND TYPES
- The suspension system of an automobile was one which
separates the wheel/axle Assembly from the body.
- The primary function of the suspension system was
to isolate the vehicle structure from shocks and vibration due to
irregularities of the road surface.
History
1903 Mors from Germany fitted a car with shock absorbers.
1920 Layland used torsion bars in its suspension system.
1922 Unitary construction and independent front suspension were pioneered on the Lambda. Lancia
1932 By this year ,the independent front suspension become more common in popular cars. 1948 Triumph Mayflower introduced the combined coil spring/damper unit.
1950 Ford adopted the McPherson strut independent front suspensionon MK 1 consul.
1959 Use of independent rubber suspension.
1962 Introduction of hydrostatic suspension.
Function of suspension system
- To prevent the road shocks from being transmitted to the vehicle frame.
- To preserve the stability of the vehicle in pitching or rolling.
- To safeguard the occupants from road shocks.
- To provide good road holding while driving, cornering and braking
Types of springs
1. Leaf spring
2. Coil spring
3. Torsion bars
4. Air and gas sprinG
5. Rubber spring 1. Leaf spring
Referred to as Laminated springs
since they use steel strips or lamination one over the other with reducing
length. They are also called as Semi elliptical springs as they are bent in
that form.
Leaf strips are made from strips of
spring steel . Each strip was called a leaf. They are joined together by
clamps and a central bolt. The length of each leaf decreases so that the
spring assembly act as a flexible
beam and was of uniform strength. The ends of master leaf are formed into
loops called spring eyes. One end of the spring was attached with frame through
a spring bolt passing through the eye. The other end was secured through a
shackle . The shackle helps in accommodating the change in length of the
spring.
2.Coil spring
-
A section of Spring steel rod wound in a spiral pattern or shape. Widely used in both Front and Rear suspension systems. Like large metal bed springs, these coils cushion and absorb the shocks and bumps as the vehicle was driven. They are usually found near the front wheels, but some cars have them in the rear as well. Often the Shock absorbers run up the center of the coil springs.
3. Torsion bars
- A torsion bar was a solid bar of steel which was connected to the car chassis at one end, and free to move at the other end. They could be mounted across the car or along the car .The springing motion was provided by the metal bar's resistance to twisting. u To over-simplify, stick your arm out straight and get someone to twist your wrist. Presuming that your mate doesn't snap your wrist, at a certain point, resistance in your arm (and pain) would cause you to twist your wrist back the other way. That was the principle of a torsion bar.
- Torsion bars are normally locked to the chassis and the suspension parts with splined ends. This allows them to be removed, twisted round a few splines and reinserted, which could be used to raise or lower a car, or to compensate for the natural 'sag' of a suspension system over time. They could be connected to just about any type of suspension system listed on this page. u The rendering below shows an example longitudinal torsion bar. The small lever at the far end of the torsion bar would be attached solidly to the frame to provide the fixed end. The torsion bar itself fits into that lever and the suspension arm at the front through splined holes. As the suspension at the front moves upwards, the bar twists along its length providing the springing motion.
4.Air
and gas spring
In these springs compressed air or
gasis filledin the cylinder or bellows against which the wheel movement was
transmitted through diaphragm. As soon as the wheel passes over a road
irregularity the compressed air returns the system to its original
position.
ADVANTAGES:
1. High cost .
2.Risk of breakdown.
3.Freezing of moisture in air in cold weather.
4.Greater maintenance required.
5.Rubber spring
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