UniAir is the world’s first electro-hydraulic system for fully-variable control of intake valves per cylinder and according to requirements in gasoline and diesel engines. This means the engine is always operated at optimal efficiency. UniAir reduces fuel consumption by up to 10 %, increases power by 10 % and torque by up to 15 % in the lower speed range – and these improvements are achieved while complying with the requirements of emission standards Euro 5 and 6.
How does UniAir work? In a conventional valve control system, the cams of the rotating intake camshaft ensure the valves open and close. The air required for the combustion process is controlled by the position of a throttle valve. One of the disadvantages of this technology is reduced efficiency due to pumping losses incurred in the throttle valve. In the UniAir system, the intake valves are not controlled directly by the intake camshaft, but indirectly via intermediate hydraulic chambers. These chambers open the valves by means of oil pressure. If this pressure is discharged by a controlled solenoid valve, the intake valve will not open even if the cam is in the lift phase.
Publisher: Schaeffler Technologies AG & Co. KG