steering hydraulic system

8/9/2019 Steering Hydraulic System

1/34

Prepared by:

KHAIRUL AMILIN BIN IBRAHIM

[email protected]


2/34

WHAT IS STEERING SYSTEMHAT IS STEERING SYSTEM

The steering system serves to allow changing the direction in which

the automobile is moving.


3/34

CONSTRUCTION OF STEERING SYSTEMONSTRUCTION OF STEERING SYSTEM

The Steering System divided into three mechanism :

Steering Control Mechanism

Steering Link Mechanism


4/34

CLASSIFICATION OF STEERING SYSTEMLASSIFICATION OF STEERING SYSTEM

STEERING SYSTEM

Manual Steering Type Power Steering Type

DIFFERENCE

Used Mechanical Support Used Mechanical and Hydraulic

Support

- eer ng a- Steering Gear

- Steering Linkage

- Steering Gear, Shaft And Linkage- Pump

- Pressure Hose

- eservo r


5/34

is a Hydraulic system assisting the driver in turning the

.

Designed to reduce the drivers effort needed to turn the

oil pump.

Its reduce driver fatigue and increase safety duringdriving.

Use on both pitman arm steering gear and rack-and-pinion

steer ng system.


6/34

2 major parts in power steering system

Hydraulic pump Steering gear

Another components

Hi h ressure hoses

Fluid reservoir


7/34


8/34

CONSTRUCTION OF POWER STEERING SYSTEM

Steering Linkage & Gear

Oil Reservoir

Cooler Hose

Pump

8


9/34

uses a hydraulic pump and

the steering unit to provide

wheels


10/34

The pump is driven by a belt running from the crankshaft.

Its o two t ngs:

Produces fluid pressure

steering gear.

A belt drive power

steerin um


11/34

Contains an integral (built-in) power piston and cylinder.


12/34

A B

Chamber B Hydraulic Control Valve


13/34

Electro-H draulic Power Steerin

Electric Power Steering

- -


14/34

-

Based on the rack-and-pinion hydraulic power steering

An electrically driven hydraulic pump, which substitutesthe steering pump driven so far by the vehicle engine.

Additional new components compared to the hydraulic

power steering are: Electric motor

Electronic control unit

Optional sensor for steering velocity


15/34

-


16/34

-

The pressure supply unit integrates electric motor and

.

The decoupling of the pump drive from the vehicle engine

vehicle

energy saving up to 75% depending on load distribution and

control strategy.

Additionally a variable steering boost is possible

functionally depending on steering, vehicle velocity and

other parameters.


17/34

-


18/34

-

How its work


19/34

-

this s stem delivers a naturall smooth steerin feel

the flexibility of control allowed by electric power, offersmore precise steering power characteristics

improves fuel economy since the electric powered pump

operates only when steering assist is needed.


20/34

Combines a mechanical steering system with an

steering.

,

boost, is substituted by an electrical system.

To achieve this a tor ue sensor measures the steerin wheel

torque and an electronic control unit calculates the

necessary servo torque.

The electric motor engages by a worm gear at the steeringcolumn or at the pinion and for high forces directly at the

rac y a a -an -nu gear.


21/34


22/34

Additional components:

Electric motor

- uses a worm gear to transmit the motors torque to the

.

Electronic control unit

- receives si nal from various sensor, ud es the currentvehicle condition and determines the assist current to be

applied to electric motor.

- detect the twist of the torsion bar and convert the applied

tor ue into an electrical si nal.


23/34


24/34

,

the position and rate of rotation of the steering wheel.

This information along with input from a steering torque

steering control module.


25/34

Other in uts such as vehicle s eed and in uts from the

traction control or stability control systems are factored into determine how much steering assist is required.

The control module then commands the motor to rotate acertain amount, and a sensor on the motor provides

feedback to the control module so it can monitor the

' .


26/34

Hydraulic Power Steering Electric Power Steering

Design more complicated Design more simple

Weight is more Weight is less

maintenance

Normal respond at different Better respond at different speedspeed

High prone to problems and faults Less prone to problems and faults

Extracts power from engine, so it

reduces the fuel mileage of the

Consumes power from battery

which is also charged by engine,

engine ut it consumes ess power


27/34

- -

wheel and steered wheels - no steering columns function. The s stem basicall consists of two se arate s stems:

a control system that enables the driver to control the

steerable wheels of the car

a feedback system that allows the driver to sense the reaction

of the steerable wheels in the steering wheel.


28/34

- -


29/34

The torque applied by the driver on the steering wheel is

measured by a torque measuring device and transmitted to

a processing unit.

The processing unit controls a motor (7) to produce a

torque corresponding to the torque applied by the driver

.

If the torque applied by the motor (7) to the steering gear

wheels will begin to move.


30/34

Sensors Functions

Angular position sensor - convert the angular position of a shaftor axle to an analog or digital code

Torque sensor - measuring and recording the torque on

a rotating system

- use strain gages applied to a rotatingshaft or axle


31/34

Actuators Functions

Steering actuator - to provide correct positioning andsufficient force to control the steering

Feedback Motor - to provide meaningful feedback to the

driver via steering wheel


32/34

Compact size

Improves ergonomics as less force is required by driver Im roves en ine com artment desi n flexibilit as intermediate

shaft and other components are eliminated

More precise control Reduces mechanical friction and wear

Reduces noise, vibration and harness (NVH) from the road to

Reduces weight

Steering can be installed easily for left- or right- hand drive


33/34

a ures n t e contro systems can resu t n an unstoppa e

runaway vehicle

Hi her cost

Less road feel

More complex design Uncertain reliability of electronics module


34/34

KHAIRUL AMILIN BIN IBRAHIM

[email protected]

steering hydraulic system

Documents