Influence of dissimilar radial clearances on the performance of hydrodynamic rotor-bearing systems considering misalignment effects

Influence of dissimilar radial clearances of the two end bearings on the performance of hydrodynamic rotor-bearing systems is investigated in the present paper. The rotor misalignment effects are considered. A parameter is introduced to measure the dissimilar level and three typical applied points (Case Left, Case Center, and Case Right) of external load are also investigated during the analysis. Finite difference method is adopted to solve the Reynolds-type equation and verification of the solution technique is conducted by comparison with previous work. The rotor equilibrium postures are solved at different dissimilar parameters () for the three external loading situations. Results show that dissimilar radial clearances have significant effects on rotor postures, minimum film thickness, stiffness and damping coefficients. Under unbalanced load situations (Case Right, Case Left), small values of (<1.0) will alleviate and large one (>1.0) will aggravate the misaligned effects. Meanwhile, the minimum film thickness increases with (<1.0) and decreases with (>1.0). For stiffness and damping coefficients, the variations with have no obvious rules. During the design and analysis of hydrodynamic rotor-bearing systems, the dissimilarity should be considered intensively for reaching appropriate results.