Post on 16-Aug-2020
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Different types of Steering Systems & Examples
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DIFFERENT TYPES OF STEERING SYSTEM DIFFERENT TYPES OF STEERING SYSTEM
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Steering systems/mechanisms in use
STEERING
RACK & PINION WORM & ROLLER
RACK & PINION
MANUAL
RECIRCULATING BALL & NUT
DRIVEN EPS
HYDROSTATIC PINIONDRIVEN EPS
RACK
COLUMNDRIVEN EPS
RECIRCULATINGBALL & NUT ( GEROTOR )
POWER
HYDRAULIC ELECTRICAL /
RACK & PINION WORM & ROLLER
ELECTRO-HYD
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DIFFERENT TYPES OF STEERING SYSTEM DIFFERENT TYPES OF STEERING SYSTEM
Steering systems/mechanisms in use
Hydraulic Electro-hyd Electric
1 SCREW & NUT X X
2 CAM & LEVER X X
3 WORM & ROLLER X X X
4 RECIRCULATING BALL SCREW & NUT ? ?
5 RACK & PINION
6 GEROTOR X X
MANUALSTEERING MECHANISMS IN USE SL. NO POWER-ASSISSTED
STEERING SYSTEM STEERING RATIO
CONSTANT VARIABLE
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MANUAL STEERING SYSTEMS
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Typical Mechanical Steering Systems( for “on-road vehicles )
Steering Systems
Cars / UVs
UVs/LCVs
Trucks / Bus
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POWER-ASSISSTED STEERING SYSTEMS
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Need forNeed for Power SteeringPower Steering
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NEED FOR POWER STEERING NEED FOR POWER STEERING
The need to achieve the greatest possible road safety under :
INCREASING TRAFFIC DENSITYINCREASING TRAFFIC DENSITYNEXT
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NEED FOR POWER STEERING NEED FOR POWER STEERING
The need to achieve the greatest possible road safety under :
HIGH AXLE LOADSHIGH AXLE LOADSNEXT
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NEED FOR POWER STEERING NEED FOR POWER STEERING
POOR ROAD CONDITIONSPOOR ROAD CONDITIONS
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The need to achieve the greatest possible road safety under :
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NEED FOR POWER STEERING NEED FOR POWER STEERING
All of the above situations force the driver to operate the vehicle at slow speeds ,increasing steering effort causing FATIGUE TO DRIVERS.
Judgment of a fatigued driver will be poor.
Poor judgment in driving means increasedpotential for accidents.
LED TO THE DEVELOPMENT LED TO THE DEVELOPMENT OF POWER STEERINGOF POWER STEERINGNEXT
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Benefits ofBenefits of Power SteeringPower Steering
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BENEFITS OF POWER STEERING BENEFITS OF POWER STEERING
EFFORTLESS STEERINGEFFORTLESS STEERING
15 mkg
3 mkg2 mkg
1 mkg
HCV CAR HCV CAR
STEE
RIN
G E
FFO
RTS
AT
PAR
KIN
G
MANUALSTEERING
POWERSTEERING
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BENEFITS OF POWER STEERING BENEFITS OF POWER STEERING
PRECISE & QUICK RESPONSEPRECISE & QUICK RESPONSE
LOCK TO LOCK MANUAL STEERINGTOTAL TURNS 6 TO 7
LOCK TO LOCK POWER STEERING
40
30
20
10
7 6 5 4 3 2 1 0 1 2 3 4 5 6 7
LH TURN RH TURN
TOTAL TURNS 3 TO 4
OU
TPU
T AN
GLE
(DEG
)
INPUT TURNS
SAP
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BENEFITS OF POWER STEERING BENEFITS OF POWER STEERING
ABSORBS ROAD SHOCKSABSORBS ROAD SHOCKS
Vehicle fitted with Manual Steering
Vehicle fitted with Power Steering
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BENEFITS OF POWER STEERING BENEFITS OF POWER STEERING
GREATER SAFETY AND GREATER SAFETY AND CONTROLLABILITY UNDER CRITICAL SITUATIONSCONTROLLABILITY UNDER CRITICAL SITUATIONS
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HYDRAULIC POWER STEERING SYSTEMS
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SYSTEM LAYOUT OF A TYPICAL POWER STEERINGSYSTEM LAYOUT OF A TYPICAL POWER STEERING
Power Steering Pump Power Steering
FI Gear
Power Steering Reservoir
Suction Line
Pressure
Line
ReturnLine
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Steering Systems
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Typical Box-type Power Steering System for CVs ( Tie rod behind the axle )
Reservoir
Power Steering Pump
Integral Power Steering Gear
Pitman Arm
Steering Column
Intermediate Shaft
Tie Rod Tube
Tie Rod End
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Integral (Box type) Power Steering SystemSRK
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Typical Cylinder-type Power Steering System for CVs ( Tie rod behind the axle )
(Manual)
Cylinder type Power Steering System
Steering Systems
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Typical Box-type Power Steering System for UVs ( Tie rod behind the axle )
Integral (Box type) Power Steering System
Steering Systems
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Cylinder type Power Steering System
Non-typical Cylinder-type Power Steering System for UVs( Tie rod behind the axle )
(Manual)
Steering Systems
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Typical R&P Power Steering System for Cars( Tie rod ahead of the axle )
Rack &Pinion Steering Gear
Steering Wheel
Steering Column
Intermediate ShaftTie Rods
Steering Lever
Steering Systems
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Typical R&P type Power Steering System for Cars / UVs
Integral Rack & Pinion type Power Steering System
Steering Systems
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HYROSTATIC STEERING SYSTEMS
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Typical Hydrostatic Steering System (for “off-road vehicles”)
Steering Systems
Farm Tractors / Earthmovers
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Need for Electro-Hydraulic / Electric Power Steering Systems
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•Fuel efficiency.
•Emission control @ engine idle.
•Control flexibility thro’ S/W change instead of H/W change.
•Integration with other electronic controls on vehiclee.g., ABS, TCS, ESP, etc.
Need for EHPS / EPS
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HPSbelt-driven-pump EPHS
two-speed EPHSmultispeed EPS
100%
25%
15%
10%0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%En
ergy
Con
sum
ptio
n
Energy Consumption of Different Power Steering Systems
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Electro-Hydraulic Power Steering Systems(EHPS)
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Motor-Pump-UnitSteering Gear
Feed & ReturnLines
Electro-hydraulic Power Steering System
Steering Systems
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Steering Maneuver
Load
SteeringWheel
Rack &Pinion Cylinder
-
+
SteeringValve
Feed Line
ReturnLine
Pump
E-Motor
M
Vehicle Speed
SteeringRate
ECU
Control
Principle of EHPS Systems
Steering Systems
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• Vehicle Performance / Safety
– Steering Feel Tuning i.e. Vehicle and/or Driver Setting
• Energy Saving
– Reduced Fuel Consumption (1 to 3 % Reduction)– High System Efficiency– Flow on demand and according to Vehicle Speed ( speed-pro feel )– Low energy consumption, in idle less than 50 Watt– Engine independent operation (Engine Shut Off)
• Future Application Criteria
– Interaction with other Chassis/Vehicle Control and Driver Assist Systems– Migration of EPHS-technology into EHS- and SBW-Applications– MPU-Utilization beyond Steering Applications (e.g. Active and Semi active
Chassis, Braking, Power Train (Automated Clutches and Transmissions)
EHPS BenefitsSteering Systems
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• Cost & Quality
– Component Assembly (HPS ) Module Assembly (EPHS) – Final Test in Car (HPS) Pre-tested System (EPHS) – Engine Independence (vs. Belt-Drive-Pump@ HPS)– Fail-Safe Operation incl. Protection Measures– System Responsibility lies with one Supplier– Simplified Supply Chain– Lower Maintenance and Warranty Cost
• Time to Market
– Steering System Tuning Flexibility in Development Process– Similar Packaging to existing Steering– Variable Position of Motor-Pump-Unit
EPHS Benefits (cont‘d)
Steering Systems
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Electric Power Steering Systems
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EPS - Scheme
Steering Systems
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Rack Drive Column Drive Pinion Drive
Electric Power Steering Systems
Electric Motor Electric Motor
Steering Systems
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Column Drive EPS
Motor / Reduction Gear/ ECU / Bracket - Assy
Manual R&P Stg Gear
Steering Systems
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Rack ( Belt ) Drive EPS
RCB- Screw
RCB- Nut
Belt driveMotor & ECU
Steering Systems
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END OF THE SESSION
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