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 turbomachines 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 (gamma = 10 degrees), aspect ratio ( lambda = 0.5, 0.8, 1.0), journal speed (v = 2.6, 5.2 m/s) and load variations in terms of eccentricity ratio (epsilon) 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.