Lubrication Methodswith Compliant Fuel

Multi-timing injects fresh cylinder oil into the cylinder at multiple crankshaft positions in the same engine revolution. A “distribution key” determines the quantity ratio and the minimum quantity per injection. The quantity ratio specifies which ratio of the total feed rate is injected at each crankshaft angle. The sum of the quantities injected at all the crankshaft positions is the set feed rate, so the total amount of cylinder oil injected is not increased by having multiple injections per revolution. The minimum quantity ensures that enough oil is injected at each injection for the cylinder oil to be effective.

With the changeover to compliant fuel, increased contaminants and low BN cylinder oil has resulted in a lower cleaning ability. Without efficient cleaning, there is a possibility of deposit build-up from wear particles and combustion residue leading to a worsened cylinder condition.

The automatic cleaning sequence will periodically increase the cylinder oil feed rate to facilitate better cleaning of the piston and piston rings. The increased feed rate is only injected into the piston rings. This allows a normal feed rate during the majority of operation and only increasing the feed rate during short periods, to react with and flush out wear particles and combustion residue.

The advantages of the automatic cleaning sequence are a cleaner cylinder and piston ring pack with less wear and/or a reduced “normal” feed rate compared to what could be achieved by regular lubrication, giving an overall reduced cylinder oil consumption.

The automatic cleaning sequence can be set up with multiple intervals at various durations.

At every revolution the Delta-timing algorithm can change the crankshaft angle at which cylinder oil is injected. The quantity injected at each crankshaft position is the same. A “distribution key” determines the average quantity of oil injected at each crankshaft angle over time. The quantity at a certain crankshaft angle is controlled by the ratio at which the oil is injected at that angle. E.g. if the algorithm is set to inject 40 % in the ring pack and 60 % according to SIP timing, the algorithm will inject 2 full injection into the ring pack and 3 full injections according to SIP timing over a total of 5 revolutions, as 2/5 = 40 % and 3/5 = 60 %.