Wave Journal Bearing with Compressible Lubricant—Part I: The Wave Bearing Concept and a Comparison to the Plain Circular Bearing

Abstract

To improve hydrodynamic journal bearing steady-stale and dynamic performance, a new bearing concept, the wave journal bearing, was developed at the author's lab. This concept features a waved inner bearing diameter. Compared to other alternative bearing geometries used to improve bearing performance such as spiral or herringbone grooves, steps, etc., the wave bearing's design is relatively simple and allows the shaft to rotate in either direction. A three-wave bearing operating with a compressible lubricant; i.e., gas, is analyzed using a numerical code. Its performance is compared to a plain (truly) circular bearing over a broad range of bearing working parameters, e.g., bearing numbers from 0.01 to 100. The geometry of the wave bearing gives the bearing its high load; i.e., stiffness, and stability characteristics. The wave bearing's performance is dependent upon the amplitude of the wave and the position of the waves relative to the applied load. To maximize wave bearing performance, the waves' position relative to the applied load should be carefully selected. The wave journal bearing offers better stability than the plain circular bearing' under all operating conditions and all wave-load orientations. Specifically, an unloaded journal bearing can be made to run stably in any operating regime by incorporating the wave geometry.