Furthermore, the starting air system and the cylinder lubrication system have been changed compared with the conventional engine series. A redundant computer system controls all these units. The following description will outline the main features of these systems, together with our recent development work and experience.
2.2 Hydraulic servo oil system
Engine-driven multi-piston pumps supply high-pressure lube oil to provide the necessary power for fuel injection and exhaust valve actuation and thus replace the camshaft power-wise. The multi-piston pumps are conventional, mass-produced axial piston pumps of proven reliability.
The use of engine system oil as the activating medium means that a separate hydraulic oil system is not needed, thus extra tanks, coolers, supply pumps and a lot of piping etc. can be dispensed with. However, generally the engine system oil is not clean enough for direct use in high-pressure hydraulic systems, and it might be feared that the required 6 μm filter would block up quickly.
Fig.3: General system layout for the fuel injection and exhaust valve actuation systems
