FLEXIBILITY WITHOUT COMPROMISE ELECTRIC CAM PHASING ANDREW MLINARIC 1
Hydraulic Variable Cam Phasing Systems Challenges: Large volume of oil required High oil pressure requirements Parasitic losses Low temperature operation Trend to Lower Oil Pressures in the ICE No oil pressure at stand still and cranking Oil pressure reduction to optimize fuel economy Hydraulic cam phasing relies on oil pressure for function Engine Oil Pressure (bar) Zero oil pressure at stand still Engine Speed (rpm) 2
Operating Conditions Temperature ( C) Operational area with hydraulic cam phasing Enhanced operational area with electric cam phasing Engine Speed (rpm) 3
Compact design Clearance free Light weight Brushless E Motor High ratio 1:7 132 tooth driven by E MotorCoupling E Motor Gearbox 134 tooth connected to camshaft 132 tooth connected to sprocket 4
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Challenges Engine Start Transient Operation Engine Shutdown Engine Speed Time Engine Start Engine Speed First combustion Target Angle Actual Angle Engine Speed Time 7
Engine Start Comfort 3 rd comb. Shift to early IVC quick start Exhaust lift Intake lift Engine Speed in rpm 1 st comb. 2 nd comb. Late IVC Early IVC Shift to late IVC comfort start Exhaust lift TDC Intake lift TDC Time in s Engine Start Comfort 3 rd comb. Shift to early IVC quick start Exhaust lift Intake lift Engine Speed in rpm 1 st comb. 2 nd comb. Late IVC Early IVC Shift to late IVC comfort start Exhaust lift TDC Intake lift TDC Time in s 8
Engine Start Cold Start Emissions % Change in Hydrocarbon Emissions Fixed cam position at engine start -16.7% Early IVC Late IVC Early EVC Late EVC Hydraulic Cam Phasing % Reduction of HC after 15s Current VQ vs. New VR Engine Source: JSAE 2165353 Optimized cam position Electric Cam Phasing at engine start Test results realized in Nissan JSAE Paper on benefits of Schaeffler ECP for HC reduction Engine Start Cold Start Emissions % Change in Hydrocarbon Emissions Fixed cam position at engine start -16.7% Early IVC Late IVC Early EVC Late EVC Hydraulic Cam Phasing % Reduction of HC after 15s Current VQ vs. New VR Engine Source: JSAE 2165353 Optimized cam position Electric Cam Phasing at engine start Test results realized in Nissan JSAE Paper on benefits of Schaeffler ECP for HC reduction 9
Engine Start Cold Start Emissions % Change in Hydrocarbon Emissions Fixed cam position at engine start -16.7% Early IVC Late IVC Early EVC Late EVC Hydraulic Cam Phasing % Reduction of HC after 15s Current VQ vs. New VR Engine Source: JSAE 2165353 Optimized cam position Electric Cam Phasing at engine start Test results realized in Nissan JSAE Paper on benefits of Schaeffler ECP for HC reduction Challenges Engine Start Transient Operation Engine Shutdown Engine Speed Time 1
Transient Shifting Shifting Event Comparison 14 12 Relative Cam Position ( Crank) 1 8 6 4 2 Target Angle Hydraulic Cam Phasing 1 2 3 4 5 6 Time (ms) Transient Shifting Shifting Event Comparison 14 Relative Cam Position ( Crank) 12 1 8 6 4 Infinite Fast Fast and range reaction controlled of authority shifting (>5 Crank/s) 15 1 5 Smooth shifting eliminates NVH associated with hydraulic systems 1 12 14 16 18 2 Target Angle Hydraulic Cam Phasing 1 2 3 4 5 6 Time (ms) 11
Transient Shifting Shifting Event Comparison 14 Relative Cam Position ( Crank) 12 1 8 6 4 Infinite Fast Fast and range reaction controlled of authority shifting (>5 Crank/s) 15 1 5 Smooth shifting eliminates NVH associated with hydraulic systems 1 12 14 16 18 2 Target Angle Hydraulic Cam Phasing 1 2 3 4 5 6 Time (ms) Transient Shifting Shifting Event Comparison 14 Relative Cam Position ( Crank) 12 1 8 6 4 Infinite Fast Fast and range reaction controlled of authority shifting (>5 Crank/s) 15 1 5 Smooth shifting eliminates NVH associated with hydraulic systems 1 12 14 16 18 2 Target Angle Hydraulic Cam Phasing 1 2 3 4 5 6 Time (ms) 12
Transient Shifting Shifting Event Comparison 14 Relative Cam Position ( Crank) 12 1 8 6 4 Infinite Fast Fast and range reaction controlled of authority shifting (>5 Crank/s) 15 1 5 Smooth shifting eliminates NVH associated with hydraulic systems 1 12 14 16 18 2 Target Angle Hydraulic Cam Phasing 1 2 3 4 5 6 Time (ms) Challenges Engine Start Transient Operation Engine Shutdown Engine Speed Time 13
Engine Shutdown Comfort Exhaust lift Intake lift Engine Vibration During Shutdown TDC Vibration Amplitude (g) 7 6 5 4 3 2 1-1 -2-3 Engine vibration during shutdown engine shutdown eliminated -4-5 -6-7 Hydraulic Cam Phasing 84 86 88 9 92 Time (s) Engine Shutdown Comfort Exhaust lift Intake lift Engine Vibration During Shutdown TDC Vibration Amplitude (g) 7 6 5 4 3 2 1-1 -2-3 Engine vibration during during shutdown engine shutdown eliminated -4-5 -6-7 Hydraulic Cam Phasing 84 86 88 9 92 Time (s) 14
Challenges Engine Start Transient Operation Engine Shutdown Engine Speed Time SYSTEM TOPOLOGY 15
218 Schaeffler Symposium System Topology Gearbox Hall signal Phase current Shifting angle demand mapping E Motor Engine CPU /crankshaft position CAN bus ECP Controller System Topology Gearbox Hall signal Phase connector Phase current Signal connector E Motor VCC GND Hall signal 1 Hall signal 2 Hall signal 3 Temperature signal /crankshaft position CAN bus ECP Controller 16
Schaeffler Smart E Motor Hall signal Gearbox Gearbox Phase current E Motor Smart E Motor Engine CPU Engine CPU /crankshaft position /crankshaft position CAN bus ECP Controller Schaeffler Smart E Motor Hall signal Gearbox Gearbox Phase current E Motor Smart E Motor Engine CPU Engine CPU /crankshaft position /crankshaft position CAN bus ECP Controller 17
Schaeffler Smart E Motor Combination of electric motor and controller Contains Schaeffler ECP control software and high current motor drivers Smart E Motor Gearbox Reduces cost and complexity of system Allows further integration of ECP controls on engine ECM /crankshaft position Engine CPU CAN bus Summary Oil pressure independent operation Flexible start position Comfort engine shutdown Direct replacement for hydraulic VCT systems 18
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