Many of the measures taken by automotive engine manufacturers to ensure compliance with emissions legislation have resulted in increased levels of soot particles entering the lubrication system of today's Diesel engines. Diesel lubricating oil condemnation limits are dependent upon a number of factors the primary of which, for an automotive Diesel lubricating oil, is the ability of the oil to continue to hold the soot particles in suspension at increasingly high concentration levels. However, once in suspension, high concentrations of soot particles can cause engine component wear, thus shortening engine life. For this reason, and in order to extend service intervals, it is desirable to remove these very small sub-micron pro-wear particles from the lubrication system.
Today, traditional by-pass barrier media filtration of soot particles is becoming ever less practical due to the conflict between the requirement for reduced engine compartment space claim and the need for larger barrier media filters arising from the demand for extended service intervals. Increasingly, manufacturers are looking to by-pass centrifugal oil cleaners as a compact solution for cleaning lubricating oil of soot particles. However, the design of current self-powered centrifugal oil cleaners has limitations that constrain the reduction of manufacturing costs of service parts and, more importantly, the single pass efficiency of the traditional designs.
This paper describes the development of a novel self-powered centrifugal oil cleaner that resolves many of the problems associated with traditional centrifuge design, such as having an increased single pass efficiency, lower parasitic loss on the engine, and easy service through use of low cost service parts. This paper concentrates on aspects of this novel design which are of particular relevance to the cleaning of Diesel lubricating oils in automotive engine applications. Comparative laboratory test results are presented and the advantages and disadvantages of the new design discussed.