Keynote presenter

Mr. Jean-Louis LIGIER
 Manager of Research & Development,
 Powertrain Division, Renault, France.

"Actual and modeled behavior of hydrodynamic bearings in thermal engines"

The first part of this analysis will highlight the running condition of hydrodynamic bearings used in thermal engine. To provide this overview, the various specific parameters and their values will be given in tables. To complete this panorama a synthesis of the major damages for each kind of engine bearing will be set up. Dispersive factors affecting the bearing behavior of hydrodynamic bearing as oil emulsion, dirt will be described. The second part is dedicated to numerical simulation. An overview of the more usual program with their advantage and disadvantage will be used to give the state of the art in the automotive industry. Finally, in the third part, we will match experience and simulation by using the two previous parts. A special care will be taken for damages, damages modeling, and weakness of damage prediction. From this survey, the key aspects will be detailed as contact problem in mixed lubrication, surface roughness evolution or effect on lubrication, local or global seizure. To conclude, a special emphasis is done on mixed lubrication and associated problem. From our industrial point of view, this subject has become a key point to consider designing reliable bearing.