Analytical Study of Non-Recessed Conical Hole Entry Hybrid/Hydrostatic Journal Bearing with Constant Flow Valve Restrictor

The present work studies the analysis of a non recessed hole entry conical hybrid/hydrostatic journal bearing adjusted for constant flow valve (CFV) restriction. The paper provides effectiveness between the conical bearings with hole entry operating in hybrid and hydrostatic mode. The Reynolds formulae, for the flow of fluid through the mating surfaces of a conical journal and bearing, are numerically worked out in both the modes considering the finite element analysis (FEA) and the necessary boundary preconditions. Holes in double row are marked on conical bearing circumference to accommodate the CFV restrictors, the angular distance between two holes are 30o apart from the apex. Qualitative features of the conical journal bearing system with hole entry have been elaborated to analyze bearing performance for radial load variation Wr = 0.25-2. Numerical results obtained from the present study indicate that load carrying capacity of conical bearing, operating in hydrostatic mode, is enhanced by the maximum pressure, direct fluid film damping and direct film stiffness coefficients vis-a-vis corresponding hybrid mode. &nbsp

Parametric investigations of short length hydro-dynamically lubricated conical journal bearing

Due to the growing need for compact size fluid film bearings, efforts are being made to explore the performance of hydro-dynamically lubricated short length conical journal bearing. The combined radial and axial load carrying features of these bearings emerge as a better option to replace the two separate bearings (journal and thrust pad bearings) employed in turbo-machines and other applications. Thus, in this study, attempts have been made to investigate the performance of conical hydrodynamic journal bearing by using finite element analysis. The bearings have been investigated for semi-cone angle (γ = 10°), aspect ratio (λ = 0.5, 0.8, 1.0), journal speed (v = 2.6, 5.2 m/s) and load variations in terms of eccentricity ratio (ε) up to 0.6. Results have been presented in terms of radial and axial load carrying capacity, stiffness coefficients, damping coefficients and threshold speed. Results from the present study reveal that load carrying capacity is improved with higher aspect ratio; whereas threshold speed decreases with the increase of eccentricity ratio and aspect ratio