Aerodynamic Model Prediction And Static Performance Measurement Of Separation-type Bump Foil Thrust Bearing

Gas bump foil bearing has been widely used in high speed gas turbines, and so far, there are fourgenerations of gas journal bearing, however, gas thrust bearing has received very little research andattention. In order to improve the utility of gas thrust bearing to engineering applications, in this paper,a new type gas thrust bearing is studied. By the discussing of load capacity and friction torque, staticcharacteristic analysis and bump foil structure optimization have been completed.Compressibility isothermal Reynolds equation considering slip boundary condition and gas filmthickness equation including top foil deformation are established. The equations of bump foil and topfoil defomiation have been derived, and the mold of bump foil is proved to be reasonable through theexperiment of bearing structure stiffness. This paper uses Matlab software to programme to solve thecouping of foil elastic deformation equation and compressibility Reynolds equation by FiniteDifference Method (FDM) and Successive over Relaxation (SOR). Then the load capacity and frictiontorque is presented, and the modeling results have shown good agreement with foreign conclusionsand experimental data, which proves accurate and reasonable of the calculation methods. According tothe relationship curve of bearing structure parameters and static characteristic, the maximum bearingcapacity and smaller friction torque could be obtained with suitable range of parameters.Top foil and bump foil are desigened and manufactured, and finally the entirety thrust bearing isassembled. Based on the gas journal bearing test-rig, a special test-bench for thrust bearing isdesigned and built. The thrust pad axial vibration characteristic is tested. Bearing friction torque, axialdisplacement as well as load capability is measured in variety shaft speeds.