Vibration characteristics analysis of liquid hydrogen lubricating herringbone spiral-grooved thrust bearing considering cavitation

The liquid-lubricated spiral-grooved thrust bearing is widely applied in rotational devices with high speed. In the bearing, hydrodynamic effect induced cavitation and axial clearance undulation interact with each other. The load capacity, friction torque, stiffness, and other bearing parameters oscillate with the periodic undulation of clearance. The oscillation of bearing performance induces instability of high rotational speed devices, which can lead to serious mechanical failure. In this investigation, the coupling effect of cavitation and sinusoidal oscillating clearance on high-speed spiral-grooved thrust bearing performance is numerically researched. The influence of vibration period, clearance amplitude, and equilibrium clearance height on bearing performance is acquired by comparison. The load capacity, friction torque, and other parameters are dealt with by fast Fourier transform, wavelet transform, and Hilbert-Huang transform. The transient, frequency, and time-frequency characteristics of bearing performances are analyzed and compared. According to the analytical results of the load capacity, the influence extent of these three vibration factors on the bearing performance is evaluated. The structure of herringbone spiral grooved thrust bearing should be optimized to acquire better load and cavitation performances under vibration conditions.