A New Approach to Flow Network Analysis of an Engine Lubrication System

In order to develop more efficient engines, it is essential to optimize the lubrication circuit of the power train systems. In this paper, during an engine design and development process, a network analysis of the engine lubrication system is described in detail. Two elements have been added to the lubrication circuit in the modified engine. These elements are hydraulic lifters and an Anti-drain valve. The effect of adding and changing the mentioned elements and increasing the bearing clearance has been investigated on oil pump capacity. Also, chain tensioner and anti-drain valve as two new important components in the lubrication system have been investigated as well as other components from tribological point of view. Improving chain tensioner material from Nitride Butyl Rubber to Poly-Amid and changing the oil jet hole position and diameter, reduce the intensity of wear to the standard level without significant decreasing of main galley pressure. Adding an anti-drain valve near hydraulic lifter gallery decreases the time which oil needs to reach lifters with sufficient pressure at engine startup. The analyses are done by Flowmaster7.6 and AVL-EXCITE7.02 software and an accessory code. Finally, theoretical results are validated by a completely controlled lubrication functional test.