MAN Diesel & Turbo
Eaton Pumps Help Increase Efficiency of World’s Largest Diesel Engines
“With Eaton pumps in tow and without a camshaft, MAN diesel engines are reducing fuel consumption and emissions over traditional camshaft-equipped engines.”
Some of the world’s largest container vessels are gulping down less fuel and reducing their carbon footprint, thanks in part to Eaton’s expertise in providing efficient hydraulic power at sea.
MAN Diesel & Turbo of Copenhagen, Denmark, and its licensees are relying on Eaton Hydrokraft axial piston pumps to provide the hydraulics muscle for MAN Diesel’s massive 12K98ME marine diesel engines that propel oceangoing vessels operating all over the world. The engines are 84 feet long and 50 feet high, weigh in at a whopping 2,300 tons, and deliver close to 100,000 horsepower!
Each two-stroke engine is equipped with five Hydrokraft pumps made by Eaton’s Wehrheim, Germany, facility.
With 75% of the market share in marine diesel-engine design, MAN Diesel approached Eaton with pump requirements for its revolutionary 12K98ME “Intelligent Engines” that operate without a camshaft.
Eaton engineers learned that MAN Diesel needed piston pumps to take over the duties of the camshaft at the heart of the engine’s electrohydraulic system. Engineers at MAN Diesel explained that the green engine needed highperforming pumps that would control fuel injection and exhaust valve actuation that otherwise would be controlled by mechanical components.They said that by providing continuously variable fuel injection and valve timing via high-performing pumps, the camshaftless design has unlimited flexibility, which enables the Intelligent Engine to reduce fuel consumption and emissions.
Because the OEM designs its engines to run around the clock for up to five years, it required pumps that would operate reliably for more than 30,000 hours at full ratings.
“If the pumps fail, the vessel shuts down,” says Eaton’s Markus Meitinger, engineer— Hydrokraft products, “so MAN Diesel needed assurance that Eaton pumps would provide trouble-free, non-stop service.”
Another challenge was the fact that the propeller of oceangoing vessels is directly connected to the engine’s crankshaft, meaning that when a ship is running astern, the direction of engine rotation needs to be reversed.
“Since our pumps are drive by the engine’s crankshaft as well, they had to be capable of operating clockwise and counterclockwise for mooring, which was a considerable challenge for open-circuit pumps,” Meitinger says. “And because of the requirement to change rotation direction, another challenge presented itself. Cavitations had to be prevented, which could occur due to pulling effects of the adjacent oil volume.
Eaton’s Hydrokraft PVWS- 500 pumps with 500 cc/rev displacement and maximum operating pressure of 350 bar were selected for the application. Their heavyduty design and maximum efficiency ensure a 32,000- hour service life, while operating at full ratings for most of the duration.
Eaton collaborated with the University of Dresden to design a custom valve plate that would enable the Hydrokraft pumps to run counterclockwise as well as clockwise. Thanks to the university’s engineering support and exhaustive testing, the pumps operate in two quadrants with increased efficiency, even while running in an open circuit.
By implementing an additional check-valve block, cavitations were prevented by creating a shortcut to the pump inlet before outlet pressure is too low.
Once its research and development work is complete, MAN Diesel sells engine-build licenses to ship and engine builders worldwide. To date, Eaton pumps are at sea on container vessels made by Hyundai Heavy Industries and Doosan Engine, both of South Korea.
Eaton pumps will also be a power source in the shipbuilding aftermarket. According to MAN Diesel specifications, the Intelligent Engines must be overhauled every five years, including complete pump change outs.