Both effective and efficient: Potential of variable Valve Train Systems for Heavy Duty Diesel engines to meet future Ultra Low NO x emission requirements

Schaeffler is inventing a new electromechanical, discretely switchable valve lift system for commercial vehicle applications: the Schaeffler eRocker Arm System. This modular valve train system can be integrated easily in existing engine setups regardless of the camshaft position and number. It can support exhaust aftertreatment by rapid heat-up and efficient thermal management at extended low load operation. To meet future emission legislations, Schaeffler and IAV investigated various thermodynamic strategies via GT Power on a 12.2 l inline six-cylinder heavy duty engine. Innovative valve lift strategies like early intake valve closure in combination with secondary exhaust valve opening are compared to existing conventional strategies like intake air throttling and combustion phasing. The results show significant potential to increase the exhaust temperature with optimized fuel consumption.