Theory of binary spiral-grooved gas bearings

Viscous gas flow in the clearance of a bearing with spiral grooves of different depths on both working surfaces is investigated. In the boundary conditions for the velocities the first- and second-order slip effects are taken into account on the basis of the Cercignani-Slezkin method. An essentially nonlinear differential equation determining the law of pressure variation in the active zone of the bearing is derived. The theory developed is compared with experiment [1] with reference to the example of a physical model with closed center and conclusions concerning the advantages of binary models are drawn.