Volvo experience of automotive low friction surfaces

Transcription

1 Volvo experience of automotive low friction surfaces Volvo Group Volvo Trucks Renault Trucks Mack Trucks UD Trucks Buses Construction Equipment Volvo Penta Volvo Aero Financial Services Volvo 3P Volvo Powertrain Volvo Parts Volvo Logistics Volvo Information Technology Volvo Group Real Estate Volvo Business Services

2 The Volvo Trademark Trucks Construction Equipment Geely Volvo Cars Buses Marine and Industrial Power Systems Aero 1953 Historic retrospect First engine overhaul km New piston New piston rings Rehoning of the liner Remachining of the valves OIL Coke&Soot Wear

3 2011 Now the customer never open the engines Oil additives 1960 How we got there Tolerances Design, Production, Cost Materials Grey cast iron and followers System Management Electronics, Cleanliness, Wear Powertrain

4 Present Scenario Decreased NO x & PM emissions Decreased CO 2 emissions Increased efficiency Better optimisation of driveline Minimised frictional losses Decreased weight New designs and materials Wear resistance Noise PM (g/kwh) EURO EURO PM=0,36 Technology Drivers 0.10 EURO EURO5 EURO4 NOx (g/kwh) EU BSFC (g/kwh) New Technology Market Requirement Present Technology NOx (g/kwh) & Bertil Stenbom

5 The Truck Engine works in very different climates, temperatures -40 to 60 0 C sandy deserts to icy polar areas high and low load high and low speed different fuels, diesel, ethanol, DME, RME, gas & Bertil Stenbom Typical passenger car fuel energy distribution Exhaust 30% Energy dissipation from driveline 30% Mechanical losses 15% To wheels 25% Piston assembly 45% Bearings 25% Pumping losses 20% Valve train 10% C M Taylor, 1998 & Bertil Stenbom

6 Diesel Engine Development Power(hk/litre) Turbo NA normally aspirated Intercooler Year & Bertil Stenbom Implications of decreased emissions and fuel consumption Lower emissions NOx PM PM, NOx Combustion EGR Aftertreatment system SCR, DPF Ultra low oil consumption Soot in oil Lower oil consumption ash-less additives low sulphur fuel Increased wear? Corrosion? Lower fuel consumption Reduce friction Combustion Reduce weight, new material Low friction coatings Lower oil viscosity Better oil additives Functional textured surfaces Higher peak pressures and temperatures Load carrying coatings Increased wear? Higher NOx levels Increased top ring load and temperature Increased wear? Increased wear? & Bertil Stenbom

7 The piston liner system 0,12 0,1 Friction coefficient 0,08 0,06 0,04 0,02 0 0,00E+00 5,00E-05 1,00E-04 1,50E-04 2,00E-04 2,50E-04 Viscosity*Speed/Load 90 MPa 0-15 m/s Computer simulation Surface Engineering Oil consumption - Liner Topography S a 500 nm S a 126 nm Better Surface Diamond Honing S a - 24 nm Tribochemistry nm Oil additives Me-polyphosphate

8 Liner Surface Optimisation

9 Coatings in reality Piston ring/cylinder liner Topography Material Form Oil! Success in machining Components? Laboratory vs on industrial surfaces Roughness & speed? Running-in. COST? New design, New finishing processes!? Lifetime/durability

10 Emissions Challenge Engine Tribology PM, EGR, new fuels etc, New chemical environment Oil consumption Lighter/less material Wear Al, Mg, coatings Functional surfaces Machining Textured surfaces Lubricant optimisation Start-Stop ISG&ISAM System knowledge Coatings Running in The future Environmentally driven development Better efficiency Less weight Less Noise generation