Car Suspension System and its types

The chassis and body of an automobile are not directly mounted on the front and rear axles, but rather via springs and shock absorbers. This is done to dampen road shocks. The pieces that execute this job are referred to as the suspension system.

As a result, the suspension system consists of springs, shock absorbers, and mountings. A vehicle's suspension system is separated into two parts: rear-end suspension and front-end suspension.

Suspension System Types

•  Suspension System for the Front End
• The front axle suspension is rigid.
•  Front suspension is independent.
• Twin Suspension System using I-Beams
• Front Suspension with a Single I-Beam
• Torsion bar independent front-end suspension
• Type of Parallelogram Independent Front Suspension
• Trailing Arm Independent Front Suspension
• Struck and Link Type Suspension System
• Sliding Types Suspension System 
• Vertical Guide Suspension System
• Suspension System for the Rear End
• Rear suspension with longitudinal leaf springs
• Rear suspension with transverse leaf springs
• Rear coil spring suspension

1. Suspension System for the Front End

Because the front wheels not only move up and down about the automobile chassis but also swing at varied angles to the car frame for steering, front-end suspension is more sophisticated than rear-end suspension.

Each wheel is placed on a spindle that is part of the steering knuckle to allow the front wheels to swing to one side or the other for steering. The steering knuckle is then supported by upper and lower control arms that are joined to the automobile frame through ball joints.

Front-End Suspension System Varieties

There are two types of front-end suspensions.

Front Suspension with Rigid Axle

The front-wheel hubs in this style of suspension revolve on antifriction bearings on the steering spindle, which is coupled to the steering knuckles. The steering spindle and steering knuckle assemblies are hinged on the axle end to allow the steering gear to turn the wheels.

The pin that serves as the pivot of this hinge is known as the kingpin or steering knuckle pin. The construction is known as Reverse Elliot when the forked section is integral with the steering knuckle and fits over the end of the axle. The ends of the axle are forked in an Elliot-type design to hold the steering knuckle extension between the ends.

Front Independent Suspension

Each front wheel is supported independently by a coil, torsion bar, or leaf spring in this style of suspension. The majority of passenger cars today use independent front suspension, with the coil spring type being the most prevalent.

Independent Front Suspension Types

 

 Suspension System with Twin I-Beams

Aside from coil springs, many forms of front suspension are used. Another form is the dual I-beam architecture, which is utilized on several Ford truck models. A separate I beam supports the end of each front wheel.

Pivots connect the ends of the I-beams to the frame. Radius arms connect the wheel ends of the two I-beams to the frame, preventing the wheels from moving backward or forward. This sort of suspension is more adaptable.

 

Front Suspension with a Single I-Beam

In larger cars, a single I-beam front suspension is used. Each end of the I-beam includes a hole through which a kingpin is assembled to hold the steering knuckle in place. A leaf spring supports each end of the I-beam.

 

Torsion bar Independent Front Suspension

A steel rod known as a torsion bar acts as a spring in this sort of suspension system, keeping the upper and lower control arms parallel under load. The rod's front end is hexagonal in form to fit snugly into an aperture in the lower control arm.

Its back response is also hexagonal in shape, allowing it to fit snugly into a hole in an anchor attached to the frame cross member. The hexagonally formed end of the torsion bar is concealed by a seal.

The forces on the wheel assembly's outer end of the lower control arm-twist the torsion bar. The torsion bar is intended to balance these forces and keep the lower arm at a specific height.

A tightening mechanism at the anchor end twists the rod via an adjustable bolt and swivels to alter the height. Strut rods are used to hold the suspension in place.

This suspension can defend against road shock by twisting the lower arm around the torsion bar. The arm returns to normal when the wheels are no longer under stress.

 

Independent Front Suspension using Parallelogram Type

The technology is referred to as parallelogram-type independent front suspension. It is made composed of an upper and lower link that is connected by a stub axle carrier.

The bottom link is usually more prominent than the higher one, and they may or may not be parallel. This system keeps the track width constant as the wheels rise and fall, reducing tire wear caused by sideways scrubbing.

 

Suspension System of Struck and Link Type

Because the loading points are widely distributed, this type of suspension system is unique for integral body design. The standard top link is replaced with a flexible attachment, and the telescopic damper serves as the kingpin. The Mac Pherson System suspension system provides a moderate rolling action and absorbs shocks well.

 

Independent Front Suspension with Trailing Arms

With a modest variation in wheelbase and caster angle, the trailing arm independent front suspension maintains a steady track and wheel attitude. A coil spring is connected to the trailing arm, which is connected to the shaft that houses the wheel hub. The spring is wound and unwound as the wheel goes up and down. In some designs, a torsion bar has been utilized in place of coil springs.

 

Suspension System with Sliding Types

The stub axle in this sort of suspension system can travel up and down as well as rotate within the frame components. The track, wheel attitude, and wheelbase stay constant while the wheel rises and falls.

 

Suspension System with Vertical Guides

The kingpin in the vertical guide suspension system is linked directly to the frame's cross member. It can move up and down, compressing and expanding springs.

 

Front Suspension with Coil Springs

Coil spring front suspension comes in three varieties.

Coil Spring Front Suspension Type 1

The coil spring of the first type is positioned between the upper and lower control arms. The lower control arm is attached to the automobile frame only at one spot.

Coil Spring Front Suspension Type 2

 The coil spring in the second type is positioned between the upper and lower control arms. The lower control arms are attached to the automobile frame in two places.

Coil Spring Front Suspension Type 3

The coil spring in the third kind is located between the upper control arm and the spring tower or housing that is part of the front-end sheet metal work.

 

2. Suspension System for the Rear End

The three types of rear-end suspensions often found in cars are as follows.

 

Rear End Suspension with Longitudinal and Transverse Leaf Springs

In current automobiles, longitudinal leaf spring and coil spring rear-end suspensions are standard. When transverse leaf spring rear-ends suspension is used in conjunction with the Hotchkiss drive, the leaf springs must be robust and resilient enough to transmit the driving impulse and torque while also resisting sideways movement and holding the body's spring weight.

To optimize the vehicle's side, the spring weight is kept as light as feasible. Because the springs typically do not support the wheels, rims, tires, brakes, and rear axles, the weight of these components is referred to as the spring weight. U-bolts secure the spring to the rear-axle housing, and each end is pivoted to the frame via eyes produced in the ends of the longest leaf.

A bolt secures one end of the longleaf to the front hanger, while spring shackles hold the other end to the rear hanger. The hangers are both bolted to the frame. The spring lengthens when compressed and shortens when expanded. A shackle compensates for the spring's length fluctuation.

The rebound clips are installed in the middle of the spring length. They are loose enough to allow the leaves to glide on top of each other, yet tight enough to keep the leaves together when spring returns. Bushings or anti-friction material, such as bronze or rubber, are typically used in the spring eyes.

Rear End Suspension with Coil Springs

The illustration depicts the coil spring rear suspension. This suspension is always combined with a torque tube, torque reaction link, or torque rod drive. As a result, no driving thrust or twist is applied to the coil springs.

Stabilizers and radius rods are also employed to relieve all loads except those operating vertically on the coil springs. When the car is unstable, the stabilizer avoids excessive roll or sideways movement.

The radius rod maintains lateral alignment of the rear axle and frame. The coil springs are held in place by pan-shaped brackets spring seats that are fastened to the rear axle.

Rear End Suspensions with De-Dion and Independent Type Coil Springs

The illustration depicts De-Dion and independent coil spring rear-end suspensions. The stiff De-Dion tube is linked longitudinally by two parallel links and laterally by a watt linkage in (A). The tube keeps the track at the same width.

De-Dion suspension is not independent because a tubular axle links and supports both wheels.

Suspension System Functions

• To prevent the vehicle from tilting or rolling while in motion.
• To protect the occupants from road shocks.
• The suspension system keeps road shocks from transferring to the vehicle frame.
• To give excellent road holding when driving, cornering, and braking.
• To keep proper steering geometry.

Suspension System Requirements

• The needed stability is commensurate with the minimum deflection.     
• Comparability to other vehicle components such as frame wheelbase and steering linkage
• Wheel hop to a minimum.
•  Low operating and maintenance costs.
•  Low initial investment.
• Weight limit
• Wear is minimal.