Different Types of Steering Systems & Examples PDF

20/21 Mar’09 Different types of Steering Systems & Examples 1 SRK DIFFERENT TYPES OF STEERING SYSTEM...

20/21 Mar’09 Different types of Steering Systems & Examples 1 SRK DIFFERENT TYPES OF STEERING SYSTEM 20/21 Mar’09 Steering systems/mechanisms in use STEERING MANUAL POWER RACK & PINION WORM & ROLLER HYDRAULIC ELECTRICAL / PREV ELECTRO-HYD RECIRCULATING BALL & NUT RACK & PINION WORM & ROLLER RACK & PINION RECIRCULATING HYDROSTATIC COLUMN PINION BALL & NUT ( GEROTOR ) DRIVEN EPS DRIVEN EPS RACK NEXT DRIVEN EPS 2 SRK 1 DIFFERENT TYPES OF STEERING SYSTEM 20/21 Mar’09 Steering systems/mechanisms in use STEERING SYSTEM STEERING RATIO SL. NO STEERING MECHANISMS IN USE POWER-ASSISSTED MANUAL CONST ANT VARIABLE Hydrau lic 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 3 SRK 20/21 Mar’09 MANUAL STEERING SYSTEMS 4 SRK 2 Steering Systems 20/21 Mar’09 Typical Mechanical Steering Systems ( for “on-road vehicles ) Cars / UVs Trucks / Bus UVs/LCVs 5 SRK 20/21 Mar’09 POWER-ASSISSTED STEERING SYSTEMS 6 SRK 3  20/21 Mar’09 Need for Power Steering 7 SRK 20/21 Mar’09 NEED FOR POWER STEERING The need to achieve the greatest possible road safety under : PREV NEXT INCREASING TRAFFIC DENSITY 8 SRK 4  20/21 Mar’09 NEED FOR POWER STEERING The need to achieve the greatest possible road safety under : PREV NEXT HIGH AXLE LOADS 9 SRK 20/21 Mar’09 NEED FOR POWER STEERING The need to achieve the greatest possible road safety under : PREV POOR ROAD CONDITIONS 10 SRK 5  20/21 Mar’09 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. PREV Poor judgment in driving means increased potential for accidents. LED TO THE DEVELOPMENT NEXT OF POWER STEERING 11 SRK 20/21 Mar’09 Benefits of Power Steering 12 SRK 6  20/21 Mar’09 BENEFITS OF POWER STEERING 15 mkg STEERING EFFORTS AT PARKING 3 mkg 2 mkg 1 mkg HCV CAR HCV CAR MANUAL POWER STEERING STEERING EFFORTLESS STEERING 13 SRK 20/21 Mar’09 BENEFITS OF POWER STEERING LOCK TO LOCK MANUAL STEERING TOTAL TURNS 6 TO 7 LOCK TO LOCK POWER STEERING TOTAL TURNS 3 TO 4 40 OUTPUT ANGLE (DEG) 30 20 10 7 6 5 4 3 2 1 0 1 2 3 4 5 6 7 INPUT TURNS LH TURN RH TURN SAP PRECISE & QUICK RESPONSE 14 SRK 7  20/21 Mar’09 BENEFITS OF POWER STEERING Vehicle fitted with Vehicle fitted with Manual Steering Power Steering ABSORBS ROAD SHOCKS 15 SRK 20/21 Mar’09 BENEFITS OF POWER STEERING GREATER SAFETY AND CONTROLLABILITY UNDER CRITICAL SITUATIONS 16 SRK 8  20/21 Mar’09 HYDRAULIC POWER STEERING SYSTEMS 17 SRK Steering Systems 20/21 Mar’09 SYSTEM LAYOUT OF A TYPICAL POWER STEERING Power Steering Reservoir Retur n Line PREV Suction Line re ssu Pre ne Li NEXT Power Steering Pump Power Steering 18 FI Gear SRK 9  20/21 Mar’09 Typical Box-type Power Steering System for CVs ( Tie rod behind the axle ) Steering Column Reservoir Intermediate Shaft Power Steering Pump Integral Power Steering Gear Tie Rod Tube Pitman Arm Tie Rod End Draglink Integral (Box type) Power Steering System 19 SRK 1 Steering Systems 20/21 Mar’09 Typical Cylinder-type Power Steering System for CVs ( Tie rod behind the axle ) (Manual) Cylinder type Power Steering System 20 SRK 10 Steering Systems 20/21 Mar’09 Typical Box-type Power Steering System for UVs ( Tie rod behind the axle ) Integral (Box type) Power Steering System 21 SRK Steering Systems 20/21 Mar’09 Non-typical Cylinder-type Power Steering System for UVs ( Tie rod behind the axle ) (Manual) Cylinder type Power Steering System 22 SRK 11 Steering Systems 20/21 Mar’09 Typical R&P Power Steering System for Cars ( Tie rod ahead of the axle ) Steering Wheel Rack &Pinion Steering Gear Steering Column Tie Rods Intermediate Shaft Steering Lever 23 SRK Steering Systems 20/21 Mar’09 Typical R&P type Power Steering System for Cars / UVs Integral Rack & Pinion type Power Steering System 24 SRK 12  20/21 Mar’09 HYROSTATIC STEERING SYSTEMS 25 SRK Steering Systems 20/21 Mar’09 Typical Hydrostatic Steering System (for “off-road vehicles”) Farm Tractors / Earthmovers 26 SRK 13  20/21 Mar’09 Need for Electro-Hydraulic / Electric Power Steering Systems 27 SRK 20/21 Mar’09 Need for EHPS / EPS Fuel efficiency. Emission control @ engine idle. Control flexibility thro’ S/W change instead of H/W change. Integration with other electronic controls on vehicle e.g., ABS, TCS, ESP, etc. 28 SRK 14  20/21 Mar’09 Energy Consumption of Different Power Steering Systems 100% 90% 100% 80% Energy Consumption 70% 60% 50% 40% 30% 25% 20% 15% 10% 0% 10% HPS belt-driven-pump EPHS two-speed EPHS multispeed EPS 29 SRK 20/21 Mar’09 Electro-Hydraulic Power Steering Systems (EHPS) 30 SRK 15 Steering Systems 20/21 Mar’09 Electro-hydraulic Power Steering System Steering Gear Motor-Pump-Unit Feed & Return Lines 31 SRK Steering Systems 20/21 Mar’09 Principle of EHPS Systems Steering Maneuver Vehicle Speed Steering Rate Steering Wheel Feed Line Steering Valve + Return - Line E-Motor Pump M ECU Control Load Rack & Cylinder Pinion 32 SRK 16 Steering Systems 20/21 Mar’09 EHPS Benefits 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) 33 SRK Steering Systems 20/21 Mar’09 EPHS Benefits (cont‘d) Cost & Quality – Component Assembly (HPS ) Î Module Assembly (EPHS) – Final Test in Car (HPS) Î 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 34 SRK 17  20/21 Mar’09 Electric Power Steering Systems 35 SRK Steering Systems 20/21 Mar’09 EPS - Scheme 36 SRK 18 Steering Systems 20/21 Mar’09 Electric Power Steering Systems Electric Motor Electric Motor Rack Drive Column Drive Pinion Drive 37 SRK Steering Systems 20/21 Mar’09 Column Drive EPS Motor / Reduction Gear/ ECU / Bracket - Assy Manual R&P Stg Gear 38 SRK 19 Steering Systems 20/21 Mar’09 Rack ( Belt ) Drive EPS Motor & ECU Belt drive RCB- Nut RCB- Screw 39 SRK 20/21 Mar’09 END OF THE SESSION 40 SRK 20