Power steering systems use hydraulic or electric power to reduce the amount of force needed to steer a vehicle. Hydraulic power steering uses high-pressure fluid to assist the steering mechanism, while electric power steering uses an electric motor. Both systems include a steering wheel, steering gearbox, and linkages. Hydraulic systems can be integral, with a torsion bar and spool valve, or linkage-type for trucks. Electric power steering has a motor, control unit with sensors, and assists steering through battery power when the wheel is turned.

1. POWER STEERING

2. INTRODUCTION
• In automobiles, power steering (also known as
power assisted steering (PAS) or steering assist
system).
• It helps drivers to steer easily by reducing the
steering effort of the steering wheel.
• Hydraulic or electric actuators added to control the
energy to the steering mechanism, so the driver
needs to provide only less effort while driving.

3. Power Steering Systems
• Power assist – (power steering) – uses hydraulic or electric
power to help the driver applied steering force.
• In the power steering system, a continuously operating pump
provides hydraulic pressure when needed.
• At the steering wheel is turned, valves are operated to admit
this hydraulic pressure to a cylinder and transmitted to the
steering linkage.
• Both steering system have
– Steering wheel.
– Steering gear box.
– Steering linkages.

6. Types of power steering system
1. HYDRAULIC POWER STEERING.
 Integral power steering.
 Linkage power steering.
2. ELECTRIC 0R ELECTRONIC POWER STEERING.

7. HYDRAULIC POWER STEERING
• Hydraulic power steering uses high pressure
fluids for assisting the steering movement.
• It uses a plunger type arrangement for its
working.
• When the driver turns the steering wheel, it
opens up the flow or pressurized fluid in such a
way that helps to turns the wheels in the
required direction.

8. 1.Integral type power steering
• It consists of a spool valve, rotary valve and a torsion bar.
• The torsion bar is attached to the end of the worm shaft.
• When the steering wheel is turned, the torsion bar twists.
• This moves the spool slightly, opening passages which
move high pressure fluid to the side of the piston where
hydraulic assist is required.
• When there is no power-assist action, the spool valve is in
the neutral position.
• The integral type is more widely used.

9. Torsion Bar
Torsion Bar

11. torsion bar in steering

12. 2.Linkage type power steering
• In this type of steering the power system is
attached between the frame of the vehicle
and the steering linkage.
• Usually it must be installed at the factory as
the vehicle is built.
• The linkage type is widely used on trucks.

14. ELECTRIC 0R ELECTRONIC POWER
STEERING
• Electric power steering works with the help of
an Electric Motor and a control unit which has
some sensors.
• The motor runs on battery and will use
electric power to assist the movement of
steering when the driver turns the wheel.

16. Working principle of electronic power steering

17. ELECTRONIC STEERING CONTROL UNIT

19. Hydraulic Power Steering V/S Electric
Power Steering
1. Hydraulic Power Steering System is complicated compared with Electric Power Steering.
2. Hydraulic Power Steering System usually weighs more than Electric Power Steering.
3. Hydraulic Power Steering uses hydraulic fluids for operation whereas there is no such fluid needed
for Electric Power Steering, thus Electric Power Steering needs less maintenance compared to
hydraulic power steering.
4. Electric Power Steering gives better response at different speeds as compared to Hydraulic Power
Steering.
5. Electric Power Steering is less prone to problems and faults and are more durable as compared to
Hydraulic power steering.
6. Hydraulic power steering extracts power from engine, so it reduces the fuel mileage of the engine.
Electric power steering consumes power from battery which is also charged by engine, but it
consumes less power compared to Hydraulic power steering. So a car having Electric power
steering will give more mileage than one with Hydraulic power steering.