Abstract:The journal bearings of the star gear drive system of the geared turbofan (GTF) engine are the key components of the driving system.In order to improve the lubrication performance of GTF journal bearings,the analysis models of three kinds of oil feedings inlet schemes were established,including two holes (two oil inlets),three holes of the same diameter (three oil inlets with the same diameter as the two holes scheme) and three holes of the same area (three oil inlets with the same total area as the two holes scheme).The effect of different oil inlet schemes on load carrying capacity,frictional power loss,oil flow rate,oil film pressure and temperature distribution of GTF bearings was investigated using ANSYSFluent.The results show that obvious negative pressure phenomenon occurs in the bearing oil film pressure.The maximum oil film pressure of the scheme of three holes of the same area is the largest,the oil flow rate of the scheme of three holes of the same diameter is the largest,while the scheme of two holes posses the largest load carrying capacity and the smallest oil flow rate.The maximum oil film temperature is near the oil inlet groove in the lower right corner of the bearing.The maximum oil film temperature and the maximum oil film temperature rise of the scheme of three holes of the same area are the smallest.Considering the load carrying capacity and oil flow rate,the lubricating performance of the scheme of two holes is the best for GTF journal bearings.