Different types of Steering Systems + Examples (1).pdf

20/21 Mar’09Different types of Steering Systems & Examples 1 SRK 20/21 Mar’09 DIFFERENT TYPES OF STEERING SYSTEM Steering systems/mechanisms in use STEERING MANUAL PREV RACK & PINION POWER WORM & ROLLER RECIRCULATING BALL & NUT NEXT HYDRAULIC RACK & PINION WORM & ROLLER RECIRCULATING BALL & NUT HYDROSTATIC ( GEROTOR ) ELECTRICAL / ELECTRO-HYD RACK & PINION COLUMN DRIVEN EPS PINION DRIVEN EPS RACK DRIVEN EPS 2 SRK 1 20/21 Mar’09 DIFFERENT TYPES OF STEERING SYSTEM Steering systems/mechanisms in use STEERING SYSTEM STEERING RATIO SL. NO STEERING MECHANISMS IN USE Electro-hyd Electric 1 SCREW & NUT X X 2 CAM & LEVER X X 3 WORM & ROLLER X X 4 RECIRCULATING BALL SCREW & NUT ? ? 5 RACK & PINION 6 GEROTOR MANUAL POWER-ASSISSTED Hydrau lic CONST ANT VARIABLE X X X 3 SRK 20/21 Mar’09 MANUAL STEERING SYSTEMS 4 SRK 2 20/21 Mar’09 Steering Systems 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 . Judgment of a fatigued driver will be poor. PREV Poor judgment in driving means increased potential for accidents. NEXT LED TO THE DEVELOPMENT OF POWER STEERING 11 SRK 20/21 Mar’09 Benefits of Power Steering 12 SRK 6 .increasing steering effort causing FATIGUE TO DRIVERS. 20/21 Mar’09 BENEFITS OF POWER STEERING STEERING EFFORTS AT PARKING 15 mkg 3 mkg 2 mkg 1 mkg HCV CAR HCV MANUAL STEERING CAR POWER 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 OUTPUT ANGLE (DEG) 40 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 Manual Steering Vehicle fitted with 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 20/21 Mar’09 Steering Systems SYSTEM LAYOUT OF A TYPICAL POWER STEERING Power Steering Reservoir Retur n Line PREV Suction Line NEXT Power Steering Pump re ssu Pre ne Li Power Steering FI Gear 18 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 Tie Rod Tube Integral Power Steering Gear Pitman Arm Tie Rod End Draglink Integral (Box type) Power Steering System 19 1 SRK 20/21 Mar’09 Steering Systems Typical Cylinder-type Power Steering System for CVs ( Tie rod behind the axle ) (Manual) Cylinder type Power Steering System 20 SRK 10 . 20/21 Mar’09 Steering Systems Typical Box-type Power Steering System for UVs ( Tie rod behind the axle ) Integral (Box type) Power Steering System 21 SRK 20/21 Mar’09 Steering Systems Non-typical Cylinder-type Power Steering System for UVs ( Tie rod behind the axle ) (Manual) Cylinder type Power Steering System 22 SRK 11 . 20/21 Mar’09 Steering Systems 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 20/21 Mar’09 Steering Systems 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 20/21 Mar’09 Steering Systems Typical Hydrostatic Steering System (for “off-road vehicles”) Farm Tractors / Earthmovers 26 SRK 13 . TCS. •Control flexibility thro’ S/W change instead of H/W change. •Emission control @ engine idle.g. •Integration with other electronic controls on vehicle e. ABS. etc.. 28 SRK 14 . ESP.20/21 Mar’09 Need for Electro-Hydraulic / Electric Power Steering Systems 27 SRK Need for EHPS / EPS 20/21 Mar’09 •Fuel efficiency. 20/21 Mar’09 Energy Consumption of Different Power Steering Systems 100% 100% Energy Consumption 90% 80% 70% 60% 50% 40% 25% 30% 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 . 20/21 Mar’09 Steering Systems Electro-hydraulic Power Steering System Steering Gear Motor-Pump-Unit Feed & Return Lines 31 SRK 20/21 Mar’09 Steering Systems 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 & Pinion Cylinder 32 SRK 16 . g. Belt-Drive-Pump@ HPS) Fail-Safe Operation incl. Braking. 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 . 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. Active and Semi active Chassis.20/21 Mar’09 Steering Systems EHPS Benefits • Vehicle Performance / Safety – Steering Feel Tuning i.and SBW-Applications – MPU-Utilization beyond Steering Applications (e.e. Power Train (Automated Clutches and Transmissions) 33 SRK 20/21 Mar’09 Steering Systems 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. 20/21 Mar’09 Electric Power Steering Systems 35 SRK 20/21 Mar’09 Steering Systems EPS .Scheme 36 SRK 18 . Assy Manual R&P Stg Gear 38 SRK 19 .20/21 Mar’09 Steering Systems Electric Power Steering Systems Electric Motor Rack Drive Electric Motor Column Drive Pinion Drive 37 SRK 20/21 Mar’09 Steering Systems Column Drive EPS Motor / Reduction Gear/ ECU / Bracket . Nut RCB.20/21 Mar’09 Steering Systems Rack ( Belt ) Drive EPS Motor & ECU Belt drive RCB.Screw 39 SRK 20/21 Mar’09 END OF THE SESSION 40 SRK 20 .