Eaton has announced its Vehicle Group has introduced a complete portfolio of variable valve actuation (VVA) technologies to help commercial vehicle manufacturers meet forthcoming emissions regulations in China. The regulations are expected to be significantly more stringent than current standards. 

“Automakers that manufacture vehicles for the China market are researching how to achieve future emissions regulations,” said Fabiano Contarin, product director, Commercial Vehicle Valvetrain, Eaton’s Vehicle Group. “Eaton is the right partner to support this effort because of our considerable experience helping European and U.S. auto and truck makers develop emissions-reducing technologies."

Eaton’s VVA solutions are based on two building blocks: 1) a rocker with a switchable capsule, and 2) a split rocker for full deactivation. By combining these two building blocks, several VVA strategies can be utilized in virtually any engine architecture – single and dual overhead cam, as well as cam-in-block engines – and engine displacement ranging from 2.0 liters to 15.0 liters.  

Cylinder deactivation (CDA) is a VVA technology that involves deactivating the intake and exhaust valve opening, as well as the fuel injection on some cylinders when an engine is running at low load. This increases the temperature of the exhaust gases, allowing the nitrogen oxide (NOx) aftertreatment to remain efficient at low load and decrease carbon dioxide (CO₂) emissions. 

CDA is an ideal solution for commercial vehicles that make frequent stops, such as sanitation or delivery trucks. It decreases both NOx and CO₂ simultaneously, making it more efficient than other technologies that cut NOx at the expense of increased CO₂. CDA can reduce NOx by more than 40% and CO₂ by 5%-8%.

Eaton also offers Late Intake Valve Closing (LIVC), which delays the closing of the intake valve, so the effective compression ratio is lower than the expansion ratio. LIVC increases the thermal efficiency of the engine, improving fuel economy and reducing CO2 emissions. Reducing the amount of airflow through the engine with a shorter intake stroke raises the exhaust temperature by 40 degrees Celsius, contributing to the thermal management of the aftertreatment. Overall, LIVC can reduce CO2 by 1%-2%, and is most efficient for applications such as over-the-road trucks.