The influence of spiral groove parameters on the performance of new hybrid gas foil spiral groove thrust bearings: Experimental study

Traditional gas foil thrust bearings often face the challenge of inadequate load capacity when under high load conditions and cannot be used in high power and heavy load turbomachinery with large external axial forces. Aiming to enhance the bearing load capability, this paper proposes a novel hybrid gas foil spiral groove thrust bearing (GFSGTB), which retains the advantages of simple structure of gas foil thrust bearing and uses the spiral groove on the top foil surface as an auxiliary pressurization mechanism of the bearing, so that the bearing load capability can be further improved by using the pumping effect and circumferential ladder effect of the spiral groove on the basis of taper dynamic pressure effect. In addition, the gas foil spiral groove thrust bearing with different spiral groove structures were designed and a bearing performance test rig was built to measure the load capability, bearing stiffness and frictional power loss of the gas foil spiral groove thrust bearing. The research in this paper focuses on the static characteristics of bearings. The test results indicate that: the load capability of gas foil spiral groove thrust bearings at N = 12 is increased by 76.84 % and the frictional power loss is reduced by 65.26 % compared with that of non-groove gas foil thrust bearings. When groove width ratio B_g = 0.051, the bearing load capability raised by 93.09 % and the frictional power loss decreases by 70.08 %. When groove depth h_g = 30 μm, the bearing load capability is raised by 82.57 % and the frictional power loss is decreases by 75.73 %. Additionally, the GFSGTB load capacity quick calculation equation is obtained by fitting according to the test results in this paper, which can quickly and accurately get the bearing load capacity of GFSGTB, and the error is less than 10 %. The results of this study can provide suggestions for significantly increasing the load capacity of gas foil thrust bearings.