Integrated Numerical Analysis on the Performance of a Hybrid Gas-Lubricated Bearing Utilizing Near-Field Acoustic Levitation

Aerodynamic bearings utilizing near-field acoustic levitation, as a novel hybrid gas-lubricated bearing, can operate with high precision and high rotational speed with low power loss and wear. This article systematically studied the acting mechanisms of aerodynamic and squeeze effects on the static and dynamic characteristics of a hybrid gas-lubricated bearing. The resonance frequencies and mode shapes of the bearing were obtained from a finite element analysis and validated by published experimental measurements. The effects of static elastic deformation, dynamic elastic deformation, and bearing clearance on the load capacity were analyzed. A nonlinear numerical model coupling the air film and the structural vibration was also developed to investigate the stability of the hybrid gas-lubricated bearing. The predicted bearing load capacity shows reasonable agreement with the experimental data. Results show that the bearing using only the aerodynamic effect has a large load capacity but poor stability. By utilizing the squeeze film effect, especially at a proper resonance frequency, the load capacity of the hybrid gas-lubricated bearing can be improved and its stability can also be remarkably promoted.