Plain Bearings in High Performance Engines - Simulation Tools for Advanced Investigations and Layouts 2006-01-1102
The loads on the plain bearings of modern combustion engines increase continuously. Reasons for this development are increasing engine speeds on gasoline engines, growing cylinder peak pressures at diesel engines and both combined with the steady trend toward light weight concepts. The still significantly increasing power output of modern engines has to be combined with actions reducing the engine friction losses, as for example smaller bearing dimensions or lower engine oil viscosities. At the same time the comfort, lifetime and engine service interval targets are aggravating boundary conditions.
This development leads to the point, where former approaches toward plain bearing layout reach their systematic limitations - a first indication are bearing failures, which occur even though all conventional layout criteria's are fulfilled.
Further effects need to be considered to simulate the behavior of the plain bearing under the boundary conditions of a fired combustion engine.
To get an understanding of the full interaction between the system dynamics of the entire crank train system, highly sophisticated and accurate mathematical models are necessary, if the global and local structural deformation of the components and the fluid dynamics of the oil films need to be considered.
Beside this, measurements techniques are necessary to calibrate the simulation models or to support the analysis where simulation possibilities are not given.
Keeping in mind that the target is to save time and costs, FEV Motorentechnik GmbH developed a methodology of bearing analysis which is highly sophisticated on one hand, but efficient on the other hand.