Diesel variable valve actuation

LIVC - Late Intake Valve Closing

Eaton’s capsule technology can be employed to modulate the intake valve to achieve either early or late valve closing. LIVC makes effective compression ratio lower than expansion ratio, increasing efficiency while increasing exhaust temperature.

CDA - Cylinder Deactivation

By deactivating the valves on one or more cylinders, the overall air/fuel ratio is reduced. The amount of injected fuel is similar while the airflow is reduced proportionally to the number of deactivated cylinders. This works to increase the exhaust temperatures and ultimately to improve emissions through improved catalyst efficiency. Simultaneously, a fuel efficiency benefit is possible. Eaton has developed a strategy for maximizing the CDA benefit while maintaining acceptable noise, vibration, and harshness (NVH). This strategy comprises deactivating variable numbers of cylinders depending on the engine's speed and load. 

EEVO - Early Exhaust Valve Opening

Eaton’s capsule technology can be employed to modulate the exhaust valve to achieve early exhaust valve opening. By opening the exhaust valve earlier, halfway through the expansion event, a larger part of the combustion energy goes into heat, instead of mechanical work, to increase the exhaust temperature.

Actuation options

Depending on the application and customer requirements, our VVA solutions can have hydraulic or electro-mechanical actuation

Modularity

The VVA solutions presented above are indeed an application of two basic technologies of Eaton: the mechanical capsule and the split rocker. By combining these two technologies, a wide variety of VVA strategies can be realized, even beyond those presented here.

These two technologies have been picked vs alternatives, being the optimal combination of:

• Robustness and reliability
• Fast response time and immediate switching between mode (no intermediate positions)
• Maximum stiffness and lift fidelity