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UniAir

Airpath Flexibility

Unlocking the Full Potential of the UniAir System

I. Introduction

Figure 1 Current fully variable valve train systems

II. System design

Figure 2 Design of the electrohydraulic UniAir system

Figure 3 Interlinking of actuator technology and engine control unit

III. Development and application process

Figure 4 Application process

IV. Benefits of UniAir at steady-state operating points

Figure 5 Load curve on the performance map of a gasoline engine with forced induction

Figure 6 Results of engine tests at an operating point of 2,000 rpm with 2 bar of mean boost pressure, without masking, Figure 7 with masking

Figure 8 Results of engine tests at an operating point of 2,000 rpm with 13 bar of mean boost pressure

Figure 9 Air-fuel blend at an operating point of 5,000 rpm with 22 bar of mean boost pressure

Figure 10 Specific fuel consumption at an operating point of 5,000 rpm with 22 bar of mean boost pressure

Figure 11 50 % conversion point at an operating point of 5,000 rpm with 22 bar of mean boost pressure

V. Benefits of UniAir in transient operation

Figure 12 Impact of altered ignition sequence on fuel consumption during WLTC testing

Figure 13 Fuel-saving potentials afforded by transient air path regulation in the WLTC test cycle

Figure 14 Fuel-saving potentials afforded by the UniAir system in the WLTC test cycle

VI. UniAir in a hybrid system

Figure 15 Performance map results for a 100 % combustion engine drivetrain and hybrid systems in the WLTC test

Figure 16 Fuel-saving potentials afforded by UniAir in a hybrid system

VII. Summary and outlook

The digital version of the Schaeffler Symposium 2018 “Mobility for Tomorrow” conference transcript