Image shows a full engine exhaust side installation with two switchable roller finger follower (RFF) per cylinder, a single acuation shaft with different actuation lobes for the two groups of RFF, and the rotary actuator which controls the angular position of the actuation shaft. (Eaton)
Eaton goes internal with its next-generation EGR solution
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Eaton’s Internal Exhaust Gas Recirculation (iEGR) solution production-debuts in the 2020MY as a next-generation technology providing near-instantaneous heating of the selective catalytic reduction system to reduce diesel exhaust emissions.
“The iEGR technology is controlled by an electro-mechanical actuator, so operation can occur in cold conditions,” Nicola Andrisani, Eaton’s Engineering Manager of the Valvetrain Advanced Engineering Vehicle Group based in Torino, Italy, said in an Automotive Engineering interview.
Traditional systems that rely on hydraulic pressure to activate the EGR take longer to generate hotter exhaust gas, which is needed to get a selective catalytic reduction (SCR) system to its necessary operating temperatures, typically 250-500° C. An SCR after-treatment system turns diesel NOx emissions into harmless nitrogen and water.
Eaton’s iEGR system also differs from other solutions in terms of packaging requirements. “Our solution can be integrated into the cylinder head cover,” Andrisani said, noting that traditional EGR technologies are located within the cylinder block, which can result in significant costs if modifications are needed at a later date.
Key to the iEGR’s functionality is a patented Switchable Roller Rocker Arm (SRRA), one per cylinder. “Our system design has rolling surfaces instead of sliding surfaces. Two rollers are used to control the main valve lifter and another roller is used to control the iEGR,” said Andrisani.
The rolling surfaces mean lower friction, less waste energy in the engine, and lower fuel consumption.
Eaton’s system makes it possible to activate iEGR or decompression positions on a diesel engine.
“One actuator controls all the valves on one side of the engine. That means it’s possible to divide the engine into two groups. The automaker could choose to activate group one (iEGR), group two (decompression positions), or both groups,” Andrisani said. Another option for group two is an early exhaust valve opening lift, which opens the exhaust valve earlier and boosts the turbine when needed.
Eaton’s iEGR will production debut on a diesel-powered global passenger vehicle in the 2020MY, but the technology also can be used on a gasoline engine. “With Eaton’s electro-mechanical solution, a single actuator could deactivate cylinders 2 and 3, or cylinders 1 and 4. That’s a high-level of flexibility with regard to cylinder deactivation to achieve better fuel economy and lower CO2 emissions,” said Andrisani.