| dc.description.abstract | The principal results from an extensive experimental investigation of the steady state characteristics of tilting pad journal bearings are presented. The conditions examined were primarily concerned with operation at high speed (>200ft/sec) and light load (<50 psi specific pressure). The stimulus for this work was the observation of significantly higher than predicted pad temperatures in several steam turbine service applications. The bearings involved were of the conventional pressurized supply (flooded), centrally pivoted, self-aligning type, loaded between pad. High temperatures occurred on both four and five inch diameter bearings designed to operate at shaft speeds up to 14,000 rpm. To investigate this, four and five inch diameter bearings of almost identical design to the service bearings were tested in a laboratory steam turbine at shaft speeds up to 16,000 rpm. The test data acquired show the relationships that exist between the steady state characteristics of pad temperature and power loss, and the parameters of speed, bearing geometry, oil flowrate, and pad material. These results are compared with predicted values from the same tilting pad journal bearing computer program used to evaluate the service bearings. Of primary interest in the data gathered is the observation of an apparent laminar to turbulent transition region. The results verify the actual behavior of the service bearings and identify limitations of the theoretical model used for predicting steady state performance. It is anticipated that the results presented will be of use to bearing designers, and of general interest to manufacturers of rotating machinery. | en |
