Externally-Pressurized Gas-Lubricated Floating-Ring Porous Journal Bearings: Part 1: Steady State Analysis

Abstract

A new type of gas-lubricatedfloating-ring journal bearing in which thefixed bearing and the ring are both porous, has been conceived and analysed, theoretically, for the steady state Characteristics. Bearing characteristics are presented against two design parameters, namely, clearances ratio and permeability parameter. The comparison of these characteristics with those of externally-pressurized plain porous journal bearings shows that the new bearing represents, with its steady state performance, a distinctly advanced bearing design. NOTATIONThe dimensional quantities are represented by barred symbols. A symbol without a bar refers only to the non-dimensional quantity. radial clearance in plain bearing, clearance of the inner film when ring and journal are concentric (m) (Fig. 1) clearance of the outer film when ring and bearing are concentric (m) (Fig. 1) C2/C1, clearances ratioFixAy pa R2, film force components (N) hi C , , film thicknesses (m) hminC1, minimum film thickness (m) H , R , thicknesses of the ring and the bearing shell (m) [= 1, 21 subscripts for the inner and the outer clearance spaces, also for the ring and the bearing shell ambient pressure (N/m2) p i pa, pressures (subambient) in the clearance spaces (N/m2) pi* pa, pressures (subambient) in porous media of the ring and the bearing shell (N/m2) p , pa, supply pressure (N/m2) P, ijR4w2/C, , viscous frictional power loss (W) QpR2C, @/2A, gas supply to the bearing (kg/s) ri Hi, radially outward coordinates (m) (Fig. 1)journal radius (m) R , , , R , inner and outer radii of the ring (m) ( Fig. 1) ?;. ijR4W/C, , viscous frictional torques (Nm) ui R0, gas velocity in &direction (m/s) Wp, R2, bearing load capacity (N) coordinate axes (Fig. 1) ring centre coordinates with reference to the bearing centre (m) zi C, , radially inward coordinates (m) (Fig. 1) (XR, YR)C1 = ( -~q cos $ R , -6 2 sin $R)CI, The MS wus

A steady-state performance analysis of a non-circular cylindrical floating ring journal bearing

“…The authors have also observed that the temperature of the inner film and dissipation of power are considerably higher than those of the outer film, which causes the inner film viscosity to drop more than that of the outer film. Malik 13 has theoretically analysed the gas-lubricated FRB in which bearing housing and the floating ring are both made of porous material. The author has compared the performance of the gas-lubricated FRB with the plain porous journal bearing.…”

Dynamic performance analysis of a noncircular cylindrical floating ring bearing

“…Authors have showed that the size of FRB outer clearance is a critical parameter and ring speed ratios can be greatly affected by the onset of nonlinear jumps. Malik 16 has presented the steady-state characteristics of the gas-lubricated FRB in which fixed bearing and the floating ring are both porous. Author has selected the clearance ratio and permeability parameter as the design parameters for the proposed analysis.…”