Every Steering System Explained | Power Steering, Four Bar, Ackermann, Four Wheel Steering

Ever wondered how some cars responds so

well to the driver? It because the

steering system, great handling makes

you feel safe and in control. A proper

steering system mechanism is necessary

to effectively control the vehicle with

safety during its entire speed range

without much effort. It should also be

able to tackle wide variations of road

surfaces, [music] bumps, and bounces to

the vehicle.

It is the basic feature of the vehicle

to be steered straight [music] and

maintained at that position or turned at

the driver's will without putting much

efforts to do so.

It is also necessary that the moving

vehicle is under driver's perfect

control in order to avoid any accident.

The system allows a driver to use only

light forces to steer a heavy car.

Steering is also possible by the turning

of the rear wheels which is generally

used in low-speed slow floor vehicles

[music] for lifting and transporting the

heavy parts like in the forklift.

So in this video we will explain how a

car steering system works [music] and

how the simple act of turning your

steering will makes the car corner and

also we look into steering basics

acriman steering power steering and

four-wheel steering later in this video.

The most conventional steering

arrangement is to turn the front wheels

using a hand operated steering wheel

which is positioned in front of the

driver via the steering column

which may contain universal joints to

allow it to deviate somewhat from a

straight line. Other arrangements are

found on different types of vehicles,

for example, a tiller or rear wheel

steering.

Tracked vehicles such as bulldozers and

tanks [music]

usually employ differential steering.

That is, the tracks are made to move at

different speeds or even in opposite

directions using clutches and brakes to

achieve a change of direction.

Do you know steering a vehicle is pretty

easy stuff. It seems so simple, but it's

really not. Let's take a look at what

your vehicle's moving parts are actually

doing. A group of parts called the

steering system transmits the movement

of the steering wheel down to the

steering shaft to move the wheels left

and right. Although car wheels will

don't turn at same angle. As you turn

the steering wheel, the steering shaft

rotates the pinion gear. The teeth of

the pinion gear and the steering rack

interlock as the pinion rotate. This

rotation will push the rack when the

rack moves. The attached rods and

steering knuckles act as pivot points

and turn the front tires. For examples,

rotating the steering wheel to the left

will push the rack to the right,

pivoting the front tires to the left.

The more you turn the steering wheel,

the more rack is pushed and the sharper

the turn will be. Little confusing?

Well, don't worry. You don't have to be

a mechanic to steer a vehicle, but we

wanted you to have visual of exactly

that is occurring when you make that

turn of the wheel. Although there are

many moving parts and words you have

never heard of with little effort and

the help of your steering system, it's

easy to steer your vehicle.

When we turn the front wheels, all the

vehicle wheels turn in that direction.

But why does the car follow a precise

curve after steering instead of

proceeding in a straight line? To find

the answer to this question, we need to

know the physics of the wheel.

For a wheel to work effectively, the

velocity of the wheel at the contact

point should always be zero.

This will make sure that there won't be

any slippage between the stationary road

and the wheel at the contact point. But

how can a moving wheel have zero

velocity at a point on its surface?

This condition is possible because it

has two separate types of velocities

acting on it. One is the rotational

velocity of the wheel and the other one

is a translational velocity of the

wheel. Here

you'll notice that the rotational

velocity of the car is inclined but the

translational velocities is straight.

Both the velocities have different

magnitude and directions. Due to this,

the velocities will not cancel each

other out and this will lead to

skidding. The only way to avoid this

skidding and achieve the zero velocity

condition is to make sure the

translational velocity is also inclined

and equal in the direction.

This is only possible when the whole car

turns with respect to a particular

center point.

But there's a problem when the whole car

is turning. The two front wheels of the

car will not be covering the same

distance. Here, all four wheels meet the

perfect conditions of rolling. For such

a perfect turn, the perpendicular lines

from the front wheels should meet

[music] rear wheel axis at a common

point. Here you'll notice that the

wheels of the car have different parts

of motion.

In the rear wheels, this is done with

the help of a differential gear. And in

front wheels, this is done with the help

of a design principle called the Acuran

steering.

If you observe carefully, you will note

that the angles turned by the left and

right wheels are not the same. This is

done to compensate for the different

distances [music] each of these tires

travel without slipping. This means that

for perfect steering, the left and right

wheels should turn at different angles.

Steering basics. To obtain a good

alignment, it is necessary to understand

the following factors. Camber,

caster, kingpin inclination,

tow in and tow out.

Camber, it is the angle between the

vertical axis of a wheel and the

vertical axis of the vehicle. when

viewed from the front or rear. When the

wheels are tilted outwards at the top is

called positive camber and if tilted

inward then it is called as negative

camber.

An equal camber angle is provided on

both the front wheels. With the positive

camber wheels become vertical under load

on the tire will have full contact with

the road and the tire wear will be

uniform. If the positive camber is

excessive then tires outer edge will

wear out faster. If the negative camber

is excess of the tires, inner edge will

wear out faster.

The caster angle is the angle formed by

the forward or backward tilt of the

steering axis from the vertical when

viewed from the side of the wheel. A

backward tilt is known as a positive

caster

and a forward tilt is known as a

negative caster.

If the caster is not equal on both

sides, it will cause the vehicle to pull

to the side of the wheel having a lesser

caster angle. The main purpose of caster

is to maintain directional stability and

control to increase steering stability

and to reduce drive effort to turn

[music] the vehicle.

Kingpin inclination.

The angle between the vehicle line and

center of the kingpin or steering axis

when viewed from the front of the

vehicle is known as kingpin inclination.

It must be equal on both sides. It is

greater on one side than the other. The

vehicle will tend to pull to the side

having a greater angle. The main

functions of kingpin inclination is that

it helps in self-centering of wheels

after taking a turn to provide

directional stability and also it

reduces steering effort.

Toe in and tow out. Front wheels are

slightly tilted inward. The distance is

less at the front and more at the rear.

When it is measured at the height of the

hub level, then it is called as toe in.

If the distance is more at the front and

less at the rear, then it is called toe

out.

And now let's find out how a four bar

steering and acriman steering mechanism

works.

The four bar steering mechanism consists

of a fixed link that is connected by two

short pivot links and a tie rod. There

are wheels on both sides of the

steering. When the car turns, only the

tie rod moves. In this, if you rotate

the steering wheel to the right, the tie

rod moves to the left. And if you steer

the vehicle to the left, then the tie

rod moves to the right like in opposite

direction. In this mechanism, the slip

angle will be the same. The slip angle

is the angle created from the center

line of the wheel. If both angles are

equal, then the vehicle will not turn

properly. It's because if a car

completes a full turn, the vehicle must

be in motion of circle. When the four

wheels rotate on the axis of the center

point, it is known as the true rolling

condition. The true rolling condition is

the front wheels are rotated with a

minimum slip to turn the car. In this

situation, the outer wheel of the car

will have to travel more than the inner

wheel. For this reason, we have to

rotate both the wheels at different

angles.

In acriman steering, the tie rod length

will be reduced as compared to four bar

steering. As a result, both the

operative small link will be inclined in

a way that its axis will be connected to

the rear axle center.

When you turn the vehicle, the wheels

will be turned at the different slip

angles. When you release the steering,

the vehicle straightening force helps to

bring back steering to its initial

position. In this mechanism, the wheel

turns at the different slip angle. The

four-wheel center axis will meet at the

instantaneous center point at both

sides, which helps to turn the vehicle

with the its true rolling conditions.

Power steering system. The power

steering is a system that reduces the

effort required of the driver to turn

the steering wheel. Without power

assist, the steering of most vehicles

would be extremely heavy, particularly

during low-speed maneuvers such as

pulling into a parking spot, [music]

turning a 90° corner in the city or

driving in a crowded gas station. The

first power steering system fitted to a

production car was in the 1951 Chrysler

Imperial, and the competition quickly

followed suit.

There are three types of power steering

systems are available. They are

hydraulic power steering, electric power

or motordriven power steering and

electro-hydraulic power steering.

Hydraulic power steering uses hydraulic

fluid that's pressurized by a pump

driven off the engine.

Electric power steering system or EPS

uses electric motors that draws energy

from the vehicle's electrical system to

provide the steering assistance instead

of hydraulic system.

Yes, you can drive without power

steering. That does not mean you should.

Driving without power steering for a

long time can damage your pump which be

a lot more expensive to repair. and also

parking and quick steering become

extremely [music] difficult.

The electric power steering is more

efficient and works to the point. It

improves fuel economy by a few% as the

electric motor only draws power when

needed. It eliminates the hydraulic

fluid maintenance and it also enables a

variety of features.

Four-wheel steering is a system employed

by some vehicles to improve steering

response and to increase vehicle

stability while driving at high speed or

to decrease turning radius at low speed.

In an active four-wheel steering [music]

system, all four wheels turn at the same

time when the driver steers. In most

cases, the rear wheels are steered by a

computer and actuators.

The rear wheels generally cannot turn as

far as the front wheels. At low speed,

the rear wheels turn opposite to the

front wheels. Reducing the turning

radius is sometimes critical for large

trucks, tractors, vehicles with

trailers, and passenger cars with a

large wheelbase.

So that's it. Thanks for watching. If

you still have any questions, let me

know in the comments.

Do you know suspension is one of the

most important function in your car. But

which type of suspension system will

help your car to run smoother and more

comfortable? Watch this video and find

out.