Lubrication Performances Of Thrust Bearings With PTFE-faced Pads In Hydro-generators

Metal-plastic bush is more used in the Hydro-gennerators, mill and other largeequipment in the recent years,and it has many advantages, for example a low coefficient offriction, good self-lubricating properties of PTFE as a tile surface material. Compared tothe Babbitt, the composite bearings have low friction power, conservation of resources andenvironmental pollution and other advantages, it is an ideal alternative alloy watts. Becausepeople is scarce about the knowledge of bearing lubrication, PTFE used for small andmedium un-lubrication friction bearings, the hydrodynamic lubrication bearing structuredesign also made reference to Babbitt, but PTFE and Babbitt physical and chemicalproperties very different, due to the poor thermal conductivity of plastic layer, leading bushmeasure the temperature lag, so that the alarm of bearing lubrication state temperaturedelay caused by burning accident. This problem has seriously hindered the application andpromotion of the technology. Carry metal-plastic bush bearing lubrication mechanismanalysis and lubrication design studies, has a very important engineering significance.This research effort to develop considering fluid-solid-thermal coupling of the largetilting metal-plastic tile thrust bearings lubricated contacts dimensional analysis; themetal-plastic bush thrust bearing lubrication mechanism of Hydro-generators is analyzed,development of lubrication design, and provide the theoretical basis and technical guidancefor the engineering application of this kind of bearings. The main work is as follows：(1) Establish the large tilting metal-plastic thrust bearings lubricated contact with athree-dimensional mathematical model that include flow-solid-thermal coupling. Combinedwith the numerical analysis technology, system software is based on FORTRAN.(2) The metal-plastic bush thrust bearing of Hydro-generators is the carrier forlubrication performance analysis and researching lubrication design of bearing structure.(3) Simulation analysis the temperature characteristics of the bush, research thehysteresis quality of bearing interface temperature with the bush measurement oftemperature, optimizing bearing temperature measurement system, to provide a referencetemperature alarm system design. In the analysis, we found that the formation of an oil film bush affected by the importand export sloping length of the bush, then the optimization plays an important role in thelubrication performance of the bearing capacity; The carrying capacity affected by thethickness of the PTFE layer on the bearing; in considering the bush size and manufacturingprocess, we can increase the thickness of the steel substrate properly and that can improvethe lubrication performance; increased the runner plate rotate speed is beneficial to theformation of oil film to improve the bearing load capacity, but at the same time lubricatingarea temperature also elevated with vigorous agitation of the runner plate and the increaseof load increase also reduce the oil film thickness.