Theoretical and Experimental Study on a Novel Porous Tilting Pad Gas Thrust Bearing with Umbrella-Type Dampers

To expand the application scope of gas bearings in oil-free turbomachinery, this paper presents a novel porous tilting pad gas thrust bearing (PTPGTB) with umbrella-type dampers (UDs) incorporating viscoelastic material. This damper, fabricated using additive manufacturing, can shrink like an umbrella to squeeze the viscoelastic material from all directions so as to dissipate more energy. A comprehensive theoretical model is proposed by coupling the PTPGTB model and the UD model. Dynamic load tests and load capacity tests are carried out. The experimental results generally agree with the predicted results. The effects of nominal clearance, supply pressure, rotational speed, and UD geometry parameters are discussed. The variations of hydrostatic and hydrodynamic effects in PTPGTBs with different parameters are revealed. The results show that smaller clearances, lower rotational speeds, higher supply pressures, and greater axial stiffness increase the load capacity of PTPGTBs. The research can provide a new design idea and theoretical guidance for improving the load capacity of gas thrust bearings.