| With the development of rotating machinery, such as turbo generators, journal bearing load is getting more heavier. Influence of journal bearing thermohydrodynamic effect on bearing performance and the stable operation of shaft is getting more important.One dimensional model for journal temperature calculation under synchronous whirling was set up based on the Morton Effect. Influence of whirling orbit on journal temperature distribution was analyzed. An improved method, which simplified journal temperature calculation by orbit disassembling procession, was proposed. The feasibility of the new method was verified.Three dimension CFD model for journal temperature was set up. Relationship among journal temperature and rotational speed, whirling orbit, inlet oil temperature and pressure was researched. Research results show that results of 3D model are more accurate.A model to calculate rotor thermal bend under Morton effect was set up. Reason for unsteady vibration caused by thermohydrodynamic effect was analyzed. Results show that thermohydrodynamic effects will cause rotor thermal bow and the unsteady vibration. There is large influence of shaft structure on the unsteady vibration. The unsteady vibration is more likely to occur on rotor with overhung disk.Research results also show that there is large influence of journal eccentricity on thermohydrodynamic effect. Journal eccentricity in bearing is influenced by bearing load and bearing load is influenced by bearing elevation. Thermohydrodynamic effect is more distinct in case of journal in bearing with large eccentricity.Journal temperature distribution and the unsteady vibration were tested on a rig and turbogenerators. Test results show that journal temperature difference increases with the increase of rotational speed and whirling orbit. Large whirling orbit may cause large temperature difference. Influence of bearing elevation on bearing thermohydrodynamic effect and vibration was tested. |
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