Classical Bearing Misalignment and Edge Loading: A Numerical Study of Limiting Cases

Abstract

This paper investigates transient and steady state behavior of grooveless (angularly) misaligned bearings using finite element formulations of the complete two-dimensional Reynolds equation. Performance trends of misaligned bearings are compared with their aligned counterparts within the traditional framework of classical lubrication theory. Elastic/plastic deformations, thermal effects, surface roughness, and pressure-viscosity variations are not taken into account. It is found that misaligned bearings have infinite load and moment capacity as the endplane minimum film thickness approaches zero under transient journal squeeze motion and under steady load and speed conditions. These results differ markedly from finite capacity trends reported previously in both numerical and experimental studies. Predictions of squeeze rate and load capacity based on axially aligned bearings are also shown to be sufficient to approximate squeeze rate and load capacity for misaligned bearings for an appreciable range of midplane eccentricity ratios.

Edge loading and running-in wear in dynamically loaded journal bearings

“…Previous publications discuss minimum oil film thickness, pressure distribution and thermal behaviour of misaligned journal bearings either experimentally [7] or by simulation [8,9]. Sun et al [10] experimentally investigated the behaviour of misaligned journal bearings due to elastic shaft deformation.…”

On the Characteristics of Misaligned Journal Bearings

“…Misalignment defect in internal combustion engine bearings, particularly the main crankshaft bearings, must be considered as an important parameter at the design stage. Boedo and Booker [110] in 2004 comprehensively researched the steady-state and transient performances of misaligned bearings. They found that misaligned bearings have infinite load and moment capacity as the end-plane minimum film thickness approaches zero under transient journal squeeze motion and under steady load and speed conditions.…”

Kinetic uncertainty analysis of the reheat-stop-valve mechanism with multiple factors

“…The study about spatial clearance joint on dynamic performance of the multibody systems has attracted the attention of some researchers as well. Monmousseau [15] and Boedo [16] found that misalignment and clearance inducing large change in the bearing characteristics. Pezzuti [17] presented a method to evaluate the performance of mechanism with clearance joints considering clearances, misalignments and dimensional errors.…”