Aerostatic thrust bearings with simple orifice restrictor

Aerostatic thrust bearing with porous restrictor

Diameter bearing 2R0

10^-3 m

Diameter restrictor 2R1

10^-3 m

Fly height h0

10^-6 m

Supply pressure pS

10⁶ Pa

Ambient pressure pA

10⁶ Pa

Pressure factor β

Permeability k_p

10^-15 m²

Restrictor pressure pR

Load capacity F^*

Effective bearing area Ae/A

Flow rate M

10^-6 kg/s

Thickness porous cylinder s

10^-3 m

Load capacity F

Axial stiffness S=-dF/dh

10⁶ N/m

Flow rate Q

l/min

2R1: The size of the pocket must be as small as possible to make the bearing less sensitive to instability. The minimal value of R1 is limited by Ac.

h0: A high axial bearing stiffness, self-aligning capability and the minimal flow is obtained with small fly height. The minimal value of the fly height gap is limited by bearing deflections and flatness of the bearing surface and is usually related to the bearing size.

Permeability: This material constant determines the thickness of the porous surface required to get the right pressure drop from pS to pR. The permeability can be reduced by impregnating the porous material.