Hydrodynamic lubrication analysis of journal bearing considering misalignment caused by shaft deformation

Analysis of steady-state characteristics of misaligned hydrodynamic journal bearings with isotropic roughness effect

Hydrodynamic journal bearings are essential components for supporting and guiding the rotating shafts of high-speed machinery. Manufacturing defects in assembly or thermal distortions may introduce problems during running, such as misalignment. The destructive effects of this kind of running problem have justified the development of a numerical model to predict the bearing operating characteristics under steady-state conditions. The present work presents in detail the three-dimensional thermohydrodynamic approach adopted in this study in order to consider the thermal field variations. This model also includes lubricant film rupture and reformation phenomena by conserving the mass flow rate. In addition, an experimental validation is made by comparison with measurements carried out on our test device for various operating conditions and misalignment torques. The influence of misalignment direction is also investigated by considering numerical and experimental approaches used in the study of bearing behavio...

Thermohydrodynamic Behavior of Misaligned Plain Journal Bearings: Theoretical and Experimental Approaches

Journal bearing misalignment arise generally from the shaft deformation under load, deflection of the shaft, manufacturing and assembly errors, improper installation, and asymmetric loading. During operations, misalignment has a considerable effect on the static and dynamic performances. It could cause wear, vibration and even system failure. In this article, a literature review of misalignment of the journal bearings is presented. The basic theory for the misalignment and some results for the circular journal bearing are also presented to show the general trends of the misalignment.

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On the Characteristics of Misaligned Journal Bearings

Journal bearing friction pair system is one of the most general and essential parts used in various mechanical devices. A special test bench is developed for the study on lubrication performance of cylindrical journal bearings. The effect of journal misalignment as a result of shaft bending under load is studied. The results show obvious changes at distribution and value of oil film pressure, oil film thickness and oil temperature of journal bearing due to journal misalignment. The higher the load on the shaft, the larger the journal misalignment resulted from shaft deformation, the more obvious effect on lubrication performance of journal bearing.

M. A. M. Abd-El-Rahman

Papers

An Adiabatic Solution of Misaligned Journal Bearings