Research Article
Experimental Aspects in the Vibration-Based Condition Monitoring of Large Hydrogenerators
Table 1
Main data of the generator upper journal bearing (UJB), generator lower journal bearing (LJB), and turbine journal bearing (TJB).
| Symbol | Description | Unit | UJB | LJB | TJB |
| | Number of pads | — | 16 | 16 | 12 | | Journal radius | mm | 1100 | 2600 | 1600 | | Bearing pad radius | mm | 1103 | 2604 | 1633 | | Journal speed | m/s | 10.6 | 25.1 | 15.5 | | Nominal pad clearance at standstill | µm | 500 | 950 | 200 | | Nominal pad clearance in operation | µm | 200 | 300 | 200 | | Bearing preload | — | 0.933 | 0.925 | 0.994 | | Distance trailing edge, pivot | mm | 140 | 248 | 250 | | Pad length | mm | 350 | 620 | 500 | | Pad width | mm | 400 | 310 | 500 | | Pad mass | kg | 172 | 290 | 390 | | Bearing direct stiffness (average) | GN/m | 6.70 | 2.85 | 6.70 | | Bearing global stiffness | GN/m | 0.80 | 1.25 | 1.45 | — | Lubricant type | | Lubrax Turbina Plus 50 | | Lubricant viscosity at 40°C | Pas | 0.047 | 0.047 | 0.047 | | Lubricant density at 20°C | kg/m3 | 873 | 873 | 873 | | Lubricant temperature range | °C | 40–55 | 40–55 | 40–50 |
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