Typical Strong Coupling Thrust Gas Bearings

摘要

To promote gas bearing performances, such as load carrying capacity and stiffness, an investigation combined aerodynamics and aerostatics is needed, particularly in a high speed gas bearing. In 1971 Fleming presented a hybrid gas bearing [1] with double columns orifices and a herringbone grooves and with a disturb method calculated its performance. However neither load carrying capacity nor stiffness improvement was found with a low bearing numbers (compressible numbers). On the contrary, weakened performances including load carry capacity and stiffness are witnessed under a low compressible number. This degradation is because of the aerodynamic and aerostatic coupling in a grooved gas bearing [2, 3] and it is found that if the bearing pressure ratio is too high, orifice flow can be reversed. There is little real experience to allow a statement on the significance of such a condition. Based on the principle of aerodynamic and aerostatic coupling an Out-Pump type aerodynamic/aerostatic thrust bearing has been investigated with Whipple-like theory [4] to overcome above degradation. This paper presents the configurations of three typical strong coupling thrust gas bearing and comparison to static experiment.