Aerostatic and Aerodynamic Performance of an In-Pump Spirally Grooved Thrust Bearing: Analysis and Comparisons to Static Load Experiments

Abstract

The combined effects of external pressurization and in-pump spiral grooves are studied according to the incompressible Whipple analysis; the results are examined in terms of non-dimensional parameters that bring out the interaction between the action of the spiral groove self-pressurization and that of the external pressurization through orifices. It is found that the interaction is significant when the supply pressure level to the orifices is near the peak pressure that can be reached by the spiral grooves alone. An optimized interacting design can improve the bearing stiffness. Away from the optimized interacting design, one of the two actions would dominate and the other one would cause a detraction of the bearing performance. As speed is sufficiently high, the pressurization action of spiral grooves causes the reduction of orifice flow and even its reversal. At such a condition the orifices are merely leakage paths that detract from the self-pressurization action of the spiral grooves. These predicted trends are qualitatively substantiated by tests.

KEY WORDS:

• Air Bearings
• Film Geometry
• Load-Carrying Capacity
• Thrust Bearings

Acknowledgments

Review led by Luis San Andres