Investigation into the Impact of Water Contamination and Operating Parameters on the Lubrication Performance of Thrust Bearings

Water contamination threatens the lubrication stability of thrust bearings in hydro-generator units. This study investigates the coupling effects of inlet oil temperature, rotational speed, and water content (0–200 g/L) on lubrication performance. The results show that water content below 1 g/L has negligible effect. A critical threshold of 70 g/L is identified, where pad temperature rise rate increases sharply; at 45 °C inlet temperature, outlet zone temperature reaches 73 °C, and film thickness decreases to 12 μm. A water content of 100 g/L corresponds to the maximum friction torque of 9 N·m. Increasing rotational speed enhances hydrodynamic effects; at 25 m/s and 70 g/L, peak pad temperature reaches 72 °C. When water content exceeds 100 g/L, thermal buffering of free water mitigates temperature rise, but fluctuating oil film load-carrying capacity requires vigilance. The findings provide theoretical support for condition assessment and maintenance of thrust bearings under water-contaminated conditions.