Figure 1. Schematic representation of the sliding bearings used in turbine-generator units of hydroelectric power plants
The lubrication must be perfect for a sliding bed to operate safely. In order to prevent warming and surface deterioration caused by the friction of the bearing surface, the sliding surfaces must be completely separated from each other by the oil film and the liquid friction event must take place. In order to realize the fluid friction in the sliding bearings, the conditions given below should be met by using hydrodynamic lubrication theory.
• There must be a gap in the direction of movement between the sliding bearing shell and pad.
• The sliding surfaces must be relative to each other.
• Lubricating oil should be able to show very good adhesion on the sliding surfaces.
• The sliding bearing and the pad surfaces must be processed in very good quality.
If one of the above mentioned points is not applied carefully, the oil film ruptures occur, causing major damage to the turbine generator bearing system.
In the fractures in the sliding bearing shell, it disrupts the theory of hydrodynamic lubrication and causes the oil film to rupture. The bearing shell fracture in the generator guide bearing of a hydroelectric power plant is shown in Figure 2